diff --git a/example/job.json b/example/job.json
index e1dc6167a..e36e537fa 100644
--- a/example/job.json
+++ b/example/job.json
@@ -1,9 +1,11 @@
 {
     "status": "pre-submission",
     "mode": "normal",
-    "_material": {
-        "...": "include(job/_material.json)"
-    },
+    "_materials": [
+        {
+            "...": "include(job/_material.json)"
+        }
+    ],
     "compute": {
         "...": "include(job/compute.json)"
     },
@@ -24,5 +26,8 @@
     },
     "_project": {
         "...": "include(job/_project.json)"
+    },
+    "api": {
+        "...": "include(job/_api.json)"
     }
 }
diff --git a/example/job/_api.json b/example/job/_api.json
new file mode 100644
index 000000000..5224a0d3f
--- /dev/null
+++ b/example/job/_api.json
@@ -0,0 +1,4 @@
+{
+    "userId": "jnLJpf9vJKYtFoQxc",
+    "authToken": "BvsTQ3xv-c4laO4Po3PQWsQty4GVwtDL_f2KXv6uFxz"
+}
diff --git a/example/job/input.json b/example/job/input.json
new file mode 100644
index 000000000..c7402411c
--- /dev/null
+++ b/example/job/input.json
@@ -0,0 +1,3 @@
+{
+    "...": "include(theory/ml/input.json)"
+}
diff --git a/example/job/software/ml/linear/workflow/fit_predict_band_gap.json b/example/job/software/ml/linear/workflow/fit_predict_band_gap.json
new file mode 100644
index 000000000..ba001749e
--- /dev/null
+++ b/example/job/software/ml/linear/workflow/fit_predict_band_gap.json
@@ -0,0 +1,119 @@
+{
+    "_id": "ML bandgap prediction",
+    "title": "SiGe alloy bandgap prediction",
+    "titleSlug": "Template for ML POC SiGe alloy bandgap prediction",
+    "compute": {
+        "ppn": 1,
+        "queue": "OR",
+        "timeLimit": "1:00:00",
+        "notify": "n",
+        "nodes": 1,
+        "arguments": {}
+    },
+    "model": {
+        "method": {
+            "workflow": {
+                "name": "sige alloy bandgap prediciton using least squares regression",
+                "app": "machine_learning",
+                "units": [
+                    {
+                        "flowchartId": "1",
+                        "head": true,
+                        "type": "execution",
+                        "name": "fit_MLmethod",
+                        "next": "2",
+                        "execution": {
+                            "app": {
+                                "name": "ml",
+                                "exec": "rupy",
+                                "version": "0.1.0"
+                            },
+                            "preProcessors": [],
+                            "input": [
+                                {
+                                    "fit": {
+                                        "type": "linear",
+                                        "subtype": "least_squares",
+                                        "arguments": {
+                                            "sampleWeight": true,
+                                            "trainDataSize": 0.75
+                                        }
+                                    },
+                                    "targetProperties": [
+                                        "band_gaps"
+                                    ],
+                                    "features": [
+                                        "elemental_composition",
+                                        "density"
+                                    ],
+                                    "exabyteIds": [
+                                        "3qp8j2CqCgsSa6ZKj",
+                                        "NdRNhkKWv4Xj8sxd8",
+                                        "AWLTt3qa5x6xRG353",
+                                        "cR2uFML56FL6rMf2v"
+                                    ]
+                                }
+                            ]
+                        },
+                        "results": [
+                            {
+                                "name": "predict"
+                            }
+                        ]
+                    },
+                    {
+                        "flowchartId": "2",
+                        "type": "execution",
+                        "name": "predict_property",
+                        "head": false,
+                        "execution": {
+                            "app": {
+                                "name": "ml",
+                                "exec": "rupy",
+                                "version": "0.1.0"
+                            },
+                            "preProcessors": [],
+                            "input": [
+                                {
+                                    "predict": {
+                                        "scope": "1",
+                                        "name": "predict"
+                                    },
+                                    "exabyteIds": [
+                                        "3qp8j2CqCgsSa6ZKj"
+                                    ]
+                                }
+                            ]
+                        },
+                        "results": [
+                            {
+                                "name": "band_gaps"
+                            }
+                        ]
+                    }
+                ]
+            }
+        }
+    },
+    "_project": {
+        "_id": "56c569d7fe45004bec30b5e7",
+        "name": "Project 1",
+        "owner": {
+            "_id": "sdkucJLKbsaa2ajksh",
+            "name": "demo",
+            "type": 10
+        },
+        "slug": "project-1",
+        "goldName": "exabyte-project-1"
+    },
+    "version": "0.1.0",
+    "owner": {
+        "_id": "paxJukXpDBiSRjfRZ",
+        "name": "demo",
+        "type": 10
+    },
+    "creator": {
+        "username": "demo",
+        "_id": "paxJukXpDBiSRjfRZ"
+    }
+}
diff --git a/example/job/theory/ml/_input_fit.json b/example/job/theory/ml/_input_fit.json
new file mode 100644
index 000000000..6ca48974d
--- /dev/null
+++ b/example/job/theory/ml/_input_fit.json
@@ -0,0 +1,9 @@
+{
+    "arguments": {
+        "...": "include(linear/input_fit.json)"
+    },
+    "method": {
+        "type": "linear",
+        "subtype": "least_squares"
+    }
+}
diff --git a/example/job/theory/ml/input.json b/example/job/theory/ml/input.json
new file mode 100644
index 000000000..91bd0a8c5
--- /dev/null
+++ b/example/job/theory/ml/input.json
@@ -0,0 +1,8 @@
+{
+    "...": "include(input/predict.json)",
+    "materials": {
+        "exabyteIds": [
+            "LCthJ6E2QabYCZqf3"
+        ]
+    }
+}
diff --git a/example/job/theory/ml/input/fit.json b/example/job/theory/ml/input/fit.json
new file mode 100644
index 000000000..aa9da396e
--- /dev/null
+++ b/example/job/theory/ml/input/fit.json
@@ -0,0 +1,11 @@
+{
+    "...": "include(../_input_fit.json)",
+    "type": "fit",
+    "features": [
+        "elemental_composition",
+        "electronegativity"
+    ],
+    "properties": [
+        "band_gaps"
+    ]
+}
diff --git a/example/job/theory/ml/input/predict.json b/example/job/theory/ml/input/predict.json
new file mode 100644
index 000000000..f7888fa3c
--- /dev/null
+++ b/example/job/theory/ml/input/predict.json
@@ -0,0 +1,4 @@
+{
+    "type": "predict",
+    "method": "include(../linear.json)"
+}
diff --git a/example/job/theory/ml/linear.json b/example/job/theory/ml/linear.json
new file mode 100644
index 000000000..3276c7292
--- /dev/null
+++ b/example/job/theory/ml/linear.json
@@ -0,0 +1,21 @@
+{
+    "type": "linear",
+    "subtype": "least_squares",
+    "dataFrame": {
+        "...": "include(linear/data_frame.json)"
+    },
+    "data": {
+        "perProperty": [
+            {
+                "...": "include(linear/data.json)"
+            }
+        ]
+    },
+    "precision": {
+        "perProperty": [
+            {
+                "...": "include(linear/precision.json)"
+            }
+        ]
+    }
+}
diff --git a/example/job/theory/ml/linear/data.json b/example/job/theory/ml/linear/data.json
new file mode 100644
index 000000000..3659cb6af
--- /dev/null
+++ b/example/job/theory/ml/linear/data.json
@@ -0,0 +1,27 @@
+{
+    "name": "band_gaps:indirect",
+    "coefficients": [
+        -3.339e-01,
+        2.555e-01
+    ],
+    "features": [
+        "elemental_composition",
+        "electronegativity"
+    ],
+    "intercept": [
+        0.5
+    ],
+    "scores": [
+        0.018,
+        0.513
+    ],
+    "scaler": [
+        {
+            "name": "mean",
+            "values": [
+                0.5,
+                1.95
+            ]
+        }
+    ]
+}
diff --git a/example/job/theory/ml/linear/data_frame.json b/example/job/theory/ml/linear/data_frame.json
new file mode 100644
index 000000000..9eb425587
--- /dev/null
+++ b/example/job/theory/ml/linear/data_frame.json
@@ -0,0 +1,16 @@
+{
+    "c8zG3XcnnTybfP3QQ": {
+        "electronegativity": 1.90,
+        "elemental_composition": {
+            "Ge": 0.3125,
+            "Si": 0.6875
+        }
+    },
+    "wWK2XCyivQrG8j34Z": {
+        "electronegativity": 2.00,
+        "elemental_composition": {
+            "Ge": 0.1875,
+            "Si": 0.8125
+        }
+    }
+}
diff --git a/example/job/theory/ml/linear/input_fit.json b/example/job/theory/ml/linear/input_fit.json
new file mode 100644
index 000000000..b8cff7ac4
--- /dev/null
+++ b/example/job/theory/ml/linear/input_fit.json
@@ -0,0 +1,6 @@
+{
+    "sampleWeight": true,
+    "numFeatures": 2,
+    "scaler": "StandardScaler",
+    "numSplits":3
+}
diff --git a/example/job/theory/ml/linear/precision.json b/example/job/theory/ml/linear/precision.json
new file mode 100644
index 000000000..49be13ab6
--- /dev/null
+++ b/example/job/theory/ml/linear/precision.json
@@ -0,0 +1,6 @@
+{
+    "name": "band_gaps:indirect",
+    "trainingError": 0.1,
+    "cvError": 0.3,
+    "score": 0.8
+}
diff --git a/example/job/workflow/unit/execution.json b/example/job/workflow/unit/execution.json
index 11921868c..0fbce745d 100644
--- a/example/job/workflow/unit/execution.json
+++ b/example/job/workflow/unit/execution.json
@@ -5,8 +5,7 @@
     "compute": null,
     "input": [
         {
-            "content": "K_POINTS automatic\n2 2 2 0 0 0",
-            "name": "pw_scf.in"
+            "...": "include(execution/input.json)"
         }
     ]
 }
diff --git a/example/job/workflow/unit/execution/input.json b/example/job/workflow/unit/execution/input.json
new file mode 100644
index 000000000..af6b3904f
--- /dev/null
+++ b/example/job/workflow/unit/execution/input.json
@@ -0,0 +1,4 @@
+{
+    "content": "K_POINTS automatic\n2 2 2 0 0 0",
+    "name": "pw_scf.in"
+}
diff --git a/example/material/elements/_elemental_data.json b/example/material/elements/_elemental_data.json
new file mode 100644
index 000000000..7ae6fc43b
--- /dev/null
+++ b/example/material/elements/_elemental_data.json
@@ -0,0 +1,4 @@
+{
+    "name": "valence_electrons",
+    "value": 4
+}
diff --git a/example/material/elements/element.json b/example/material/elements/element.json
new file mode 100644
index 000000000..3eee65175
--- /dev/null
+++ b/example/material/elements/element.json
@@ -0,0 +1,41 @@
+{
+    "element": "Si",
+    "properties": [
+        {
+            "name": "valence_electrons",
+            "value": 4
+        },
+        {
+            "name": "unpaired_electrons",
+            "value": 4
+        },
+        {
+            "name": "atomic_radius",
+            "value": 111.0,
+            "units": "pm"
+        },
+        {
+            "name": "electron_configuration",
+            "value": "[Ne]3s23p2"
+        },
+        {
+            "name": "electronegativity",
+            "value": 1.90
+        },
+        {
+            "name": "ionization_potential",
+            "value": 8.15,
+            "units": "eV"
+        },
+        {
+            "name": "density",
+            "value": 2.32,
+            "units": "g/cm^3"
+        },
+        {
+            "name": "cohesive_energy",
+            "value": 4.63,
+            "units": "eV/atom"
+        }
+    ]
+}
diff --git a/example/material/fingerprint.json b/example/material/fingerprint.json
new file mode 100644
index 000000000..49169cf12
--- /dev/null
+++ b/example/material/fingerprint.json
@@ -0,0 +1,17 @@
+{
+    "elemental":[
+        {
+            "...": "include(fingerprint/elemental.json)"
+        }
+    ],
+    "primary": [
+        {
+            "...": "include(fingerprint/primary.json)"
+        }
+    ],
+    "secondary": [
+        {
+            "...": "include(characteristic.json)"
+        }
+    ]
+}
diff --git a/example/material/fingerprint/elemental.json b/example/material/fingerprint/elemental.json
new file mode 100644
index 000000000..16789cc76
--- /dev/null
+++ b/example/material/fingerprint/elemental.json
@@ -0,0 +1,6 @@
+{
+    "type": "element-specific",
+    "subtype": "numeric",
+    "name": "ionization_potential",
+    "...": "include(elemental/ionization_potential.json)"
+}
diff --git a/example/material/fingerprint/elemental/ionization_potential.json b/example/material/fingerprint/elemental/ionization_potential.json
new file mode 100644
index 000000000..ae23a2a3f
--- /dev/null
+++ b/example/material/fingerprint/elemental/ionization_potential.json
@@ -0,0 +1,5 @@
+{
+    "...": "include(../schemas/element_specific.json)",
+    "name": "ionization_potential",
+    "units": "eV"
+}
diff --git a/example/material/fingerprint/primary.json b/example/material/fingerprint/primary.json
new file mode 100644
index 000000000..f7824b54e
--- /dev/null
+++ b/example/material/fingerprint/primary.json
@@ -0,0 +1,7 @@
+{
+    "type": "compound-specific-array",
+    "subtype": "numeric",
+    "category": "stoichiometric",
+    "name": "p_norms",
+    "...": "include(primary/p_norms.json)"
+}
diff --git a/example/material/fingerprint/primary/p_norms.json b/example/material/fingerprint/primary/p_norms.json
new file mode 100644
index 000000000..66b674d9e
--- /dev/null
+++ b/example/material/fingerprint/primary/p_norms.json
@@ -0,0 +1,3 @@
+{
+    "...": "include(../schemas/compound_specific_array.json)"
+}
diff --git a/example/material/fingerprint/schemas/compound_specific_array.json b/example/material/fingerprint/schemas/compound_specific_array.json
new file mode 100644
index 000000000..3bd024b7b
--- /dev/null
+++ b/example/material/fingerprint/schemas/compound_specific_array.json
@@ -0,0 +1,21 @@
+{
+    "name": "p_norms",
+    "data": [
+        {
+            "name": "p03",
+            "value": 0.693
+        },
+        {
+            "name": "p05",
+            "value": 0.671
+        },
+        {
+            "name": "p07",
+            "value": 0.667
+        },
+        {
+            "name": "p09",
+            "value": 0.667
+        }
+    ]
+}
diff --git a/example/material/fingerprint/schemas/element_specific.json b/example/material/fingerprint/schemas/element_specific.json
new file mode 100644
index 000000000..02bd8ecee
--- /dev/null
+++ b/example/material/fingerprint/schemas/element_specific.json
@@ -0,0 +1,12 @@
+{
+    "elements": [
+        {
+            "name": "Si",
+            "value": 8.15
+        },
+        {
+            "name": "Ge",
+            "value": 7.90
+        }
+    ]
+}
diff --git a/example/material/structure/atomic_data.json b/example/material/structure/atomic_data.json
index a917f223a..bc00ffbd2 100644
--- a/example/material/structure/atomic_data.json
+++ b/example/material/structure/atomic_data.json
@@ -1,18 +1,5 @@
 {
     "name": "atomic_data",
-    "valenceElectrons": {
-        "value": [
-            {
-                "id": 1,
-                "value": 4
-            },
-            {
-                "id": 2,
-                "value": 4
-            }
-        ],
-        "name": "valence_electrons"
-    },
     "charges": {
         "value": [
             {
diff --git a/example/material/structure/lattice_bravais.json b/example/material/structure/lattice_bravais.json
index 1ec9365c1..854f8798d 100644
--- a/example/material/structure/lattice_bravais.json
+++ b/example/material/structure/lattice_bravais.json
@@ -1,6 +1,6 @@
 {
-    "name": "lattice_bravais",
     "type": "CUB",
+    "name": "lattice_bravais",
     "a": 5.14,
     "b": 5.14,
     "c": 5.14,
diff --git a/schema/job.json b/schema/job.json
index 689cef77f..4c7b21960 100644
--- a/schema/job.json
+++ b/schema/job.json
@@ -74,9 +74,12 @@
             "description": "Subset of the full information about the project that this job belongs to. Included for quick access in search.",
             "$ref": "file:job/_project.json"
         },
-        "_material": {
+        "_materials": {
             "description": "Subset of the full information about the materials used inside this job.",
-            "$ref": "file:job/_material.json"
+            "type": "array",
+            "items": {
+                "$ref": "file:job/_material.json"
+            }
         },
         "version": {
             "description": "Job's schema version. Used to distinct between different schemas.",
@@ -108,6 +111,24 @@
                 "_id",
                 "title"
             ]
+        },
+        "api": {
+            "description": "REST API configuration",
+            "type": "object",
+            "properties": {
+                "userId": {
+                    "description": "user ID",
+                    "type": "string"
+                },
+                "authToken": {
+                    "description": "authentication token",
+                    "type": "string"
+                }
+            },
+            "required": [
+                "userId",
+                "authToken"
+            ]
         }
     },
     "required": [
diff --git a/schema/job/app.json b/schema/job/app.json
index 89d8e1c93..a9b585929 100644
--- a/schema/job/app.json
+++ b/schema/job/app.json
@@ -32,6 +32,9 @@
             "$ref": "file:software/vasp.json"
         },
         {
+            "$ref": "file:software/ml.json"
+	    },
+	    {
             "$ref": "file:software/shell.json"
         },
         {
@@ -40,7 +43,6 @@
     ],
     "required": [
         "name",
-        "flavor",
         "version",
         "exec"
     ]
diff --git a/schema/job/input.json b/schema/job/input.json
new file mode 100644
index 000000000..a3f2e27ce
--- /dev/null
+++ b/schema/job/input.json
@@ -0,0 +1,11 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "Execution unit object input schema",
+    "type": "object",
+    "oneOf": [
+        {
+            "description": "input schema for ml methods.",
+            "$ref": "file:theory/ml/input.json"
+        }
+    ]
+}
diff --git a/schema/job/software/ml.json b/schema/job/software/ml.json
new file mode 100644
index 000000000..2429ab9e3
--- /dev/null
+++ b/schema/job/software/ml.json
@@ -0,0 +1,27 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "default machine learning app schema",
+    "type": "object",
+    "properties": {
+        "name": {
+            "enum": [
+                "ml"
+            ]
+        },
+        "summary": {
+            "enum": [
+                "Default Machine Learning Engine"
+            ]
+        },
+        "version": {
+            "enum": [
+                "0.1.1"
+            ]
+        },
+        "exec": {
+            "enum": [
+                "rupy"
+            ]
+        }
+    }
+}
diff --git a/schema/job/theory/_methods.json b/schema/job/theory/_methods.json
new file mode 100644
index 000000000..4e1b2d1e0
--- /dev/null
+++ b/schema/job/theory/_methods.json
@@ -0,0 +1,12 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "List of all supported methods",
+    "oneOf": [
+        {
+            "$ref": "file:dft/_methods.json"
+        },
+        {
+            "$ref": "file:ml/_methods.json"
+        }
+    ]
+}
diff --git a/schema/job/theory/_models.json b/schema/job/theory/_models.json
new file mode 100644
index 000000000..a470cd277
--- /dev/null
+++ b/schema/job/theory/_models.json
@@ -0,0 +1,12 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "List of supported models",
+    "oneOf": [
+        {
+            "$ref": "file:dft.json"
+        },
+        {
+            "$ref": "file:ml.json"
+        }
+    ]
+}
diff --git a/schema/job/theory/dft/_methods.json b/schema/job/theory/dft/_methods.json
new file mode 100644
index 000000000..357181208
--- /dev/null
+++ b/schema/job/theory/dft/_methods.json
@@ -0,0 +1,12 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "List of methods",
+    "oneOf": [
+        {
+            "$ref": "file:local-orbital.json"
+        },
+        {
+            "$ref": "file:pseudopotential.json"
+        }
+    ]
+}
diff --git a/schema/job/theory/ml.json b/schema/job/theory/ml.json
new file mode 100644
index 000000000..b7fcd319a
--- /dev/null
+++ b/schema/job/theory/ml.json
@@ -0,0 +1,18 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "machine learning schema",
+    "description": "machine learning schema",
+    "properties": {
+        "type": {
+            "enum": [
+                "machine_learning"
+            ]
+        },
+        "subtype": {
+            "enum": [
+                "supervised",
+                "unsupervised"
+            ]
+        }
+    }
+}
diff --git a/schema/job/theory/ml/_input_fit.json b/schema/job/theory/ml/_input_fit.json
new file mode 100644
index 000000000..71c36c507
--- /dev/null
+++ b/schema/job/theory/ml/_input_fit.json
@@ -0,0 +1,32 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "List of input fit arguments",
+    "type": "object",
+    "properties": {
+        "method": {
+            "properties": {
+                "type": {
+                    "enum": [
+                        "linear"
+                    ]
+                },
+                "subtype": {
+                    "enum": [
+                        "least_squares",
+                        "ridge"
+                    ]
+                }
+            }
+        },
+        "arguments": {
+            "oneOf": [
+                {
+                    "$ref": "file:linear/input_fit.json"
+                }
+            ]
+        }
+    },
+    "required": [
+        "method"
+    ]
+}
diff --git a/schema/job/theory/ml/_methods.json b/schema/job/theory/ml/_methods.json
new file mode 100644
index 000000000..de59940eb
--- /dev/null
+++ b/schema/job/theory/ml/_methods.json
@@ -0,0 +1,43 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "List of methods for ML",
+    "properties": {
+        "dataFrame": {
+            "description": "data frame used to train ml method",
+            "type": "object"
+        },
+        "precision": {
+            "perProperty": {
+                "type": "array",
+                "items": {
+                    "type": "object",
+                    "properties": {
+                        "name": {
+                            "description": "characteristic property name in a flat format: eg. `band_gaps:indirect`",
+                            "type": "string"
+                        }
+                    }
+                }
+            }
+        },
+        "data": {
+            "perProperty": {
+                "type": "array",
+                "items": {
+                    "type": "object",
+                    "properties": {
+                        "name": {
+                            "description": "characteristic property name in a flat format: eg. `band_gaps:indirect`",
+                            "type": "string"
+                        }
+                    }
+                }
+            }
+        }
+    },
+    "oneOf": [
+        {
+            "$ref": "file:linear.json"
+        }
+    ]
+}
diff --git a/schema/job/theory/ml/input.json b/schema/job/theory/ml/input.json
new file mode 100644
index 000000000..54d9ed884
--- /dev/null
+++ b/schema/job/theory/ml/input.json
@@ -0,0 +1,27 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "ML methods input schema",
+    "type": "object",
+    "oneOf": [
+        {
+            "$ref": "file:input/fit.json"
+        },
+        {
+            "$ref": "file:input/predict.json"
+        }
+    ],
+    "properties": {
+        "materials": {
+            "type": "object",
+            "properties": {
+                "exabyteIds": {
+                    "description": "List of material ids corresponding to materials used for model fitting or property prediction",
+                    "type": "array"
+                }
+            }
+        }
+    },
+    "required": [
+        "materials"
+    ]
+}
diff --git a/schema/job/theory/ml/input/fit.json b/schema/job/theory/ml/input/fit.json
new file mode 100644
index 000000000..161f7ffc4
--- /dev/null
+++ b/schema/job/theory/ml/input/fit.json
@@ -0,0 +1,40 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "ML methods input schema",
+    "type": "object",
+    "allOf": [
+        {
+            "$ref": "file:../_input_fit.json"
+        }
+    ],
+    "properties": {
+        "type": {
+            "enum": [
+                "fit"
+            ]
+        },
+        "features": {
+            "description": "material features used for model fitting",
+            "type": "array"
+        },
+        "properties": {
+            "description": "target properties to predict",
+            "type": "array"
+        },
+        "method": {
+            "properties": {
+                "type": {
+                    "type": "string"
+                },
+                "subtype": {
+                    "type": "string"
+                }
+            }
+        }
+    },
+    "required": [
+        "type",
+        "features",
+        "properties"
+    ]
+}
diff --git a/schema/job/theory/ml/input/predict.json b/schema/job/theory/ml/input/predict.json
new file mode 100644
index 000000000..8aae1faf5
--- /dev/null
+++ b/schema/job/theory/ml/input/predict.json
@@ -0,0 +1,28 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "predict schema",
+    "type": "object",
+    "properties": {
+        "type": {
+            "enum": [
+                "predict"
+            ]
+        },
+        "method": {
+            "oneOf": [
+                {
+                    "description": "pre-trained ml method (when predicting) or an object describing a new one to be fit",
+                    "$ref": "file:../_methods.json"
+                },
+                {
+                    "description": "method read from workflow scope",
+                    "$ref": "file:../../../workflow/unit/_input.json"
+                }
+            ]
+        }
+    },
+    "required": [
+        "type",
+        "method"
+    ]
+}
diff --git a/schema/job/theory/ml/linear.json b/schema/job/theory/ml/linear.json
new file mode 100644
index 000000000..0b7e5aa17
--- /dev/null
+++ b/schema/job/theory/ml/linear.json
@@ -0,0 +1,41 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "linear methods schema",
+    "properties": {
+        "type": {
+            "enum": [
+                "linear"
+            ]
+        },
+        "subtype": {
+            "enum": [
+                "least_squares",
+                "ridge"
+            ]
+        },
+        "dataFrame": {
+            "$ref": "file:linear/data_frame.json"
+        },
+        "precision": {
+            "perProperty": {
+                "items": {
+                    "$ref": "file:linear/precision.json"
+                }
+            }
+        },
+        "data": {
+            "perProperty": {
+                "items": {
+                    "$ref": "file:linear/data.json"
+                }
+            }
+        }
+    },
+    "required": [
+        "type",
+        "subtype",
+        "dataFrame",
+        "precision",
+        "data"
+    ]
+}
diff --git a/schema/job/theory/ml/linear/data.json b/schema/job/theory/ml/linear/data.json
new file mode 100644
index 000000000..4ce4693ae
--- /dev/null
+++ b/schema/job/theory/ml/linear/data.json
@@ -0,0 +1,64 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "regression parameters schema",
+    "properties": {
+        "coefficients": {
+            "type": "array",
+            "description": "Array with weights/coefficients of the function for each target in property vector from the linear or non-linear fit",
+            "items": {
+                "type": "number"
+            }
+        },
+        "intercept": {
+            "type": "array",
+            "description": "list of intercepts (shift) from the linear or non-linear fit of data points",
+            "items": {
+                "type": "number"
+            }
+        },
+        "features": {
+            "type": "array",
+            "description": "Array with subset of features used in linear or non-linear fit",
+            "items": {
+                "type": "string"
+            }
+        },
+        "scores": {
+            "type": "array",
+            "description": "Array of pvalues of features used in linear or non-linear fit, https://en.wikipedia.org/wiki/P-value",
+            "items": {
+                "type": "number"
+            }
+        },
+        "scaler": {
+            "type": "array",
+            "description": "feature scaling parameters from linear/non-linear fit",
+            "items": {
+                "properties": {
+                    "name": {
+                        "description": "name of variable",
+                        "enum": [
+                            "mean",
+                            "variance"
+                        ]
+                    },
+                    "values": {
+                        "type": "array",
+                        "description": "array of values corresponding to the variable. Example: variance in training data",
+                        "items": {
+                            "type": "number"
+                        }
+                    }
+                }
+            }
+        }
+    },
+    "required": [
+        "coefficients",
+        "intercept",
+        "features",
+        "scaler",
+        "scores"
+    ]
+}
+
diff --git a/schema/job/theory/ml/linear/data_frame.json b/schema/job/theory/ml/linear/data_frame.json
new file mode 100644
index 000000000..4b5394091
--- /dev/null
+++ b/schema/job/theory/ml/linear/data_frame.json
@@ -0,0 +1,6 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "data frame for linear method (TODO: define)",
+    "type": "object"
+}
+
diff --git a/schema/job/theory/ml/linear/input_fit.json b/schema/job/theory/ml/linear/input_fit.json
new file mode 100644
index 000000000..11fc64496
--- /dev/null
+++ b/schema/job/theory/ml/linear/input_fit.json
@@ -0,0 +1,25 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "linear methods fit arguments schema",
+    "properties": {
+        "sampleWeight": {
+            "type": "boolean",
+            "description": "specify whether to scale the response variables"
+        },
+        "numSplits":{
+            "type": "number",
+            "description": "number of groups to split the training data set for cross-validation"
+        },
+        "scaler":{
+            "type":"string",
+            "description": "name of the feature scaling method for scaling input features. Eg: StandardScaler"
+        },
+        "numFeatures": {
+            "type": "number",
+            "description": "number of features to select for model training"
+        }
+    },
+    "required": [
+        "sampleWeight"
+    ]
+}
diff --git a/schema/job/theory/ml/linear/precision.json b/schema/job/theory/ml/linear/precision.json
new file mode 100644
index 000000000..5543f0398
--- /dev/null
+++ b/schema/job/theory/ml/linear/precision.json
@@ -0,0 +1,21 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "precision schema for regression",
+    "properties": {
+        "trainingError": {
+            "description": "training error of the estimator",
+            "type": "number"
+        },
+        "cvError": {
+            "description": "cross validation error of the estimator",
+            "type": "number"
+        },
+        "score": {
+            "description": "prediction score of the estimator. Eg: r2_score",
+            "type": "number"
+        }
+    },
+    "required": [
+        "trainingError"
+    ]
+}
diff --git a/schema/job/workflow/subworkflow/model.json b/schema/job/workflow/subworkflow/model.json
index f83729ea8..03ef34fd5 100644
--- a/schema/job/workflow/subworkflow/model.json
+++ b/schema/job/workflow/subworkflow/model.json
@@ -24,9 +24,9 @@
             }
         }
     },
-    "oneOf": [
+    "allOf": [
         {
-            "$ref": "file:../../theory/dft.json"
+            "$ref": "file:../../theory/_models.json"
         }
     ],
     "required": [
diff --git a/schema/job/workflow/subworkflow/model/method.json b/schema/job/workflow/subworkflow/model/method.json
index b0b1ab6bb..6b6e06cfd 100644
--- a/schema/job/workflow/subworkflow/model/method.json
+++ b/schema/job/workflow/subworkflow/model/method.json
@@ -18,12 +18,9 @@
             "type": "object"
         }
     },
-    "oneOf": [
+    "allOf": [
         {
-            "$ref": "file:../../../theory/dft/pseudopotential.json"
-        },
-        {
-            "$ref": "file:../../../theory/dft/local-orbital.json"
+            "$ref": "file:../../../theory/_methods.json"
         }
     ],
     "required": [
diff --git a/schema/job/workflow/unit/execution.json b/schema/job/workflow/unit/execution.json
index e87696f3a..caea449f8 100644
--- a/schema/job/workflow/unit/execution.json
+++ b/schema/job/workflow/unit/execution.json
@@ -15,20 +15,15 @@
             "description": "Unit's input.",
             "type": "array",
             "items": {
-                "type": "object",
-                "properties": {
-                    "name": {
-                        "description": "Input file name. e.g. pw_scf.in",
-                        "type": "string"
+                "oneOf": [
+                    {
+                        "description": "textual input (eg. for simulation engines)",
+                        "$ref": "file:execution/input.json"
                     },
-                    "content": {
-                        "description": "Content of the input file. e.g. &CONTROL    calculation='scf' ...",
-                        "type": "string"
+                    {
+                        "description": "object input (eg. for machine learning)",
+                        "$ref": "file:../../input.json"
                     }
-                },
-                "required": [
-                    "name",
-                    "content"
                 ]
             }
         }
diff --git a/schema/job/workflow/unit/execution/input.json b/schema/job/workflow/unit/execution/input.json
new file mode 100644
index 000000000..6dec40166
--- /dev/null
+++ b/schema/job/workflow/unit/execution/input.json
@@ -0,0 +1,19 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "execution unit text input schema",
+    "type": "object",
+    "properties": {
+        "name": {
+            "description": "Input file name. e.g. pw_scf.in",
+            "type": "string"
+        },
+        "content": {
+            "description": "Content of the input file. e.g. &CONTROL    calculation='scf' ...",
+            "type": "string"
+        }
+    },
+    "required": [
+        "name",
+        "content"
+    ]
+}
diff --git a/schema/material/elements/_elemental_data.json b/schema/material/elements/_elemental_data.json
new file mode 100644
index 000000000..54f60acc3
--- /dev/null
+++ b/schema/material/elements/_elemental_data.json
@@ -0,0 +1,42 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "standard elemental data",
+    "description": "properties of elements",
+    "type": "object",
+    "properties": {
+        "name": {
+            "description": "name of the property",
+            "enum": [
+                "valence_electrons",
+                "unpaired_electrons",
+                "atomic_radius",
+                "electronegativity",
+                "ionization_potential",
+                "electron_configuration",
+                "cohesive_energy",
+                "density"
+            ]
+        },
+        "value": {
+            "description": "value of the property",
+            "type": ["number", "string"]
+        },
+        "units": {
+            "oneOf":[
+                {
+                    "$ref": "file:../units.json#/definitions/length"
+                },
+                {
+                    "$ref": "file:../units.json#/definitions/energy"
+                },
+                {
+                    "$ref": "file:../units.json#/definitions/density"
+                }
+            ]
+        }
+    },
+    "required": [
+        "name",
+        "value"
+    ]
+}
diff --git a/schema/material/elements/element.json b/schema/material/elements/element.json
new file mode 100644
index 000000000..e56f921dd
--- /dev/null
+++ b/schema/material/elements/element.json
@@ -0,0 +1,22 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "Element symbol and elemental properties schema",
+    "description": "element symbols",
+    "properties":{
+        "element":{
+            "description": "element symbol",
+            "type": "string"
+        },
+        "properties":{
+            "description": "elemental properties. standard data",
+            "type": "array",
+            "items":{
+                "$ref": "file:_elemental_data.json"
+            }
+        }
+    },
+    "required":[
+        "element",
+        "properties"
+    ]
+}
diff --git a/schema/material/fingerprint.json b/schema/material/fingerprint.json
new file mode 100644
index 000000000..b0532631c
--- /dev/null
+++ b/schema/material/fingerprint.json
@@ -0,0 +1,34 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "material fingerprint schema",
+
+    "description": "collection of elemental and material descriptors. Required for performing advanced ML tasks",
+    "properties": {
+        "elemental": {
+            "type": "array",
+            "description": "elemental descriptors. Properties of constituent elements Example: atomic_radius or ionization_potential ",
+            "items": {
+                "$ref": "file:fingerprint/elemental.json"
+            }
+        },
+        "primary": {
+            "type": "array",
+            "description": "descriptors related to structure, stoichiometry and physical reference data of materials. Calculated on-the-fly ",
+            "items": {
+                "$ref": "file:fingerprint/primary.json"
+            }
+        },
+        "secondary": {
+            "type": "array",
+            "description": "characteristic properties",
+            "items": {
+                "$ref": "file:characteristic.json"
+            }
+        }
+    },
+    "required": [
+        "elemental",
+        "primary",
+        "secondary"
+    ]
+}
diff --git a/schema/material/fingerprint/_primary.json b/schema/material/fingerprint/_primary.json
new file mode 100644
index 000000000..8a1dc017e
--- /dev/null
+++ b/schema/material/fingerprint/_primary.json
@@ -0,0 +1,37 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "descriptor category schema",
+    "description": "type/subtype each primary descriptor belongs to",
+    "properties": {
+        "type": {
+            "type": "string",
+            "enum": [
+                "element-specific",
+                "compound-specific",
+                "compound-specific-array"
+            ]
+        },
+        "subtype": {
+            "description": "type of descriptor, whether it is a number or category",
+            "type": "string",
+            "enum": [
+                "numeric",
+                "nominal",
+                "ordinal"
+            ]
+        },
+        "category": {
+            "type": "string",
+            "enum": [
+                "chemical",
+                "stoichiometric",
+                "structural",
+                "electronic"
+            ]
+        }
+    },
+    "required": [
+        "type",
+        "subtype"
+    ]
+}
diff --git a/schema/material/fingerprint/elemental.json b/schema/material/fingerprint/elemental.json
new file mode 100644
index 000000000..94cbd22ee
--- /dev/null
+++ b/schema/material/fingerprint/elemental.json
@@ -0,0 +1,54 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "elemental descriptors schema",
+    "description": "collection of standard data for elements from databases. Eg: NIST physical reference data ",
+    "properties": {
+        "name": {
+            "description": "Name of the descriptor",
+            "type": "string",
+            "enum": [
+                "valence_electrons",
+                "ionization_potential",
+                "atomic_radius",
+                "electronegativity",
+                "unpaired_electrons"
+            ]
+        },
+         "type": {
+            "type": "string",
+            "enum": [
+                "element-specific"
+            ]
+        },
+        "subtype": {
+            "description": "type of descriptor, whether it is a number or category",
+            "type": "string",
+            "enum": [
+                "numeric",
+                "nominal"
+            ]
+        }
+    },
+    "oneOf": [
+        {
+            "$ref": "file:elemental/valence_electrons.json"
+        },
+        {
+            "$ref": "file:elemental/unpaired_electrons.json"
+        },
+        {
+            "$ref": "file:elemental/electronegativity.json"
+        },
+        {
+            "$ref": "file:elemental/ionization_potential.json"
+        },
+        {
+            "$ref": "file:elemental/atomic_radius.json"
+        }
+    ],
+    "required": [
+        "name",
+        "type",
+        "subtype"
+    ]
+}
diff --git a/schema/material/fingerprint/elemental/atomic_radius.json b/schema/material/fingerprint/elemental/atomic_radius.json
new file mode 100644
index 000000000..55dd88904
--- /dev/null
+++ b/schema/material/fingerprint/elemental/atomic_radius.json
@@ -0,0 +1,24 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "atomic radius schema",
+    "description": "atomic radius of each element in the material",
+    "allOf": [
+        {
+            "$ref": "file:../schemas/element_specific.json"
+        }
+    ],
+    "properties": {
+        "name": {
+            "enum": [
+                "atomic_radius"
+            ]
+        },
+        "units": {
+            "$ref":"file:../../units.json#/definitions/length"
+        }
+    },
+    "required": [
+        "name",
+        "units"
+    ]
+}
diff --git a/schema/material/fingerprint/elemental/electronegativity.json b/schema/material/fingerprint/elemental/electronegativity.json
new file mode 100644
index 000000000..44c7f233c
--- /dev/null
+++ b/schema/material/fingerprint/elemental/electronegativity.json
@@ -0,0 +1,24 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "pauling electronegativity schema",
+    "description": "electronegativity of each element in the material on pauling scale",
+    "allOf": [
+        {
+            "$ref": "file:../schemas/element_specific.json"
+        }
+    ],
+    "properties": {
+        "name": {
+            "enum": [
+                "electronegativity"
+            ]
+        },
+        "value": {
+            "type": "number"
+        }
+    },
+    "required": [
+        "name",
+        "value"
+    ]
+}
diff --git a/schema/material/fingerprint/elemental/ionization_potential.json b/schema/material/fingerprint/elemental/ionization_potential.json
new file mode 100644
index 000000000..132292c01
--- /dev/null
+++ b/schema/material/fingerprint/elemental/ionization_potential.json
@@ -0,0 +1,24 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "ionization potential schema",
+    "description": "first ionization potential of each element in the material in eV",
+    "allOf": [
+        {
+            "$ref": "file:../schemas/element_specific.json"
+        }
+    ],
+    "properties": {
+        "name": {
+            "enum": [
+                "ionization_potential"
+            ]
+        },
+        "units": {
+            "$ref": "file:../../units.json#/definitions/energy"
+        }
+    },
+    "required":[
+        "name",
+        "units"
+    ]
+}
diff --git a/schema/material/fingerprint/elemental/unpaired_electrons.json b/schema/material/fingerprint/elemental/unpaired_electrons.json
new file mode 100644
index 000000000..8f1fd3810
--- /dev/null
+++ b/schema/material/fingerprint/elemental/unpaired_electrons.json
@@ -0,0 +1,24 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "unpaired electrons schema",
+    "description": "number of unpaired electrons in each element in the material",
+    "allOf": [
+        {
+            "$ref": "file:../schemas/element_specific.json"
+        }
+    ],
+    "properties": {
+        "name": {
+            "enum": [
+                "unpaired_electrons"
+            ]
+        },
+        "value": {
+            "type": "number"
+        }
+    },
+    "required": [
+        "name",
+        "value"
+    ]
+}
diff --git a/schema/material/fingerprint/elemental/valence_electrons.json b/schema/material/fingerprint/elemental/valence_electrons.json
new file mode 100644
index 000000000..e4599ce50
--- /dev/null
+++ b/schema/material/fingerprint/elemental/valence_electrons.json
@@ -0,0 +1,24 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "valence electrons schema",
+    "description": "valence electrons in each element in the material",
+    "allOf": [
+        {
+            "$ref": "file:../schemas/element_specific.json"
+        }
+    ],
+    "properties": {
+        "name": {
+            "enum": [
+                "valence_electrons"
+            ]
+        },
+        "value": {
+            "type": "number"
+        }
+    },
+    "required": [
+        "name",
+        "value"
+    ]
+}
diff --git a/schema/material/fingerprint/primary.json b/schema/material/fingerprint/primary.json
new file mode 100644
index 000000000..ee7675b9d
--- /dev/null
+++ b/schema/material/fingerprint/primary.json
@@ -0,0 +1,56 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "primary descriptors schema",
+    "description": "collection of stoichiometric, structural, physical, electronic and chemical",
+    "allOf": [
+        {
+            "$ref": "file:_primary.json"
+        }
+    ],
+    "properties": {
+        "name": {
+            "description": "Name of the descriptor",
+            "type": "string",
+            "enum": [
+                "local_environment",
+                "element_spin_state",
+                "valence_orbital_occupancy",
+                "p_norms",
+                "elemental_composition",
+                "crystal_cell_type",
+                "material_type",
+                "is_relaxed",
+                "avg_atom_volume"
+            ]
+        }
+    },
+    "oneOf": [
+        {
+            "$ref": "file:primary/local_environment.json"
+        },
+        {
+            "$ref": "file:primary/element_spin_state.json"
+        },
+        {
+            "$ref": "file:primary/valence_orbital_occupancy.json"
+        },
+        {
+            "$ref": "file:primary/p_norms.json"
+        },
+        {
+            "$ref": "file:primary/elemental_composition.json"
+        },
+        {
+            "$ref": "file:primary/crystal_cell_type.json"
+        },
+        {
+            "$ref": "file:primary/material_type.json"
+        },
+        {
+            "$ref": "file:primary/is_relaxed.json"
+        },
+        {
+            "$ref": "file:primary/avg_atom_volume.json"
+        }
+    ]
+}
diff --git a/schema/material/fingerprint/primary/avg_atom_volume.json b/schema/material/fingerprint/primary/avg_atom_volume.json
new file mode 100644
index 000000000..c849a86cb
--- /dev/null
+++ b/schema/material/fingerprint/primary/avg_atom_volume.json
@@ -0,0 +1,24 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "Structural descriptor - average volume per atom schema",
+    "description": "Total volume divided by number of atoms. Units: ang**3 ",
+    "allOf": [
+        {
+            "ref": "file:../schemas/compound_specific.json"
+        }
+    ],
+    "properties": {
+        "name": {
+            "enum": [
+                "avg_atom_volume"
+            ]
+        },
+        "units": {
+            "$ref": "file:../../units.json#/definitions/volume"
+        }
+    },
+    "required": [
+        "name",
+        "units"
+    ]
+}
diff --git a/schema/material/fingerprint/primary/crystal_cell_type.json b/schema/material/fingerprint/primary/crystal_cell_type.json
new file mode 100644
index 000000000..4732657fb
--- /dev/null
+++ b/schema/material/fingerprint/primary/crystal_cell_type.json
@@ -0,0 +1,29 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "Structural descriptor - representation of crsytal lattice",
+    "description": "primitive or conventional or supercell. Representation differentiates between two materials with similiar composition.",
+    "allOf": [
+        {
+            "$ref": "file:../schemas/compound_specific.json"
+        }
+    ],
+    "properties": {
+        "name": {
+            "enum": [
+                "crystal_cell_type"
+            ]
+        },
+        "value": {
+            "description": "cell representation",
+            "enum": [
+                "primitive",
+                "supercell",
+                "conventional"
+            ]
+        }
+    },
+    "required": [
+        "name",
+        "value"
+    ]
+}
diff --git a/schema/material/fingerprint/primary/element_spin_state.json b/schema/material/fingerprint/primary/element_spin_state.json
new file mode 100644
index 000000000..fba470586
--- /dev/null
+++ b/schema/material/fingerprint/primary/element_spin_state.json
@@ -0,0 +1,33 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "element spin state schema schema",
+    "description": "spin state of each element in the material",
+    "allOf": [
+        {
+            "$ref": "file:../schemas/element_specific.json"
+        }
+    ],
+    "properties": {
+        "name": {
+            "enum": [
+                "element_spin_state"
+            ]
+        },
+        "elements": {
+            "items": {
+                "value": {
+                    "description": "high and low spin states correspond to states with max number of unpaired electrons with same spin and maximum number of paired spins respectively.",
+                    "enum": [
+                        "high",
+                        "intermediate",
+                        "low"
+                    ]
+                }
+            }
+        }
+    },
+    "required": [
+        "name",
+        "elements"
+    ]
+}
diff --git a/schema/material/fingerprint/primary/elemental_composition.json b/schema/material/fingerprint/primary/elemental_composition.json
new file mode 100644
index 000000000..5dcf7eab8
--- /dev/null
+++ b/schema/material/fingerprint/primary/elemental_composition.json
@@ -0,0 +1,24 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "stocihiometric descriptor, elemental composition schema",
+    "description": "composition of each element in the material",
+    "allOf": [
+        {
+            "$ref": "file:../schemas/compound_specific_array.json"
+        }
+    ],
+    "properties": {
+        "name": {
+            "enum": [
+                "elemental_composition"
+            ]
+        },
+        "value":{
+            "type": "number"
+        }
+    },
+    "required": [
+        "name",
+        "value"
+    ]
+}
diff --git a/schema/material/fingerprint/primary/is_relaxed.json b/schema/material/fingerprint/primary/is_relaxed.json
new file mode 100644
index 000000000..0ee37aa95
--- /dev/null
+++ b/schema/material/fingerprint/primary/is_relaxed.json
@@ -0,0 +1,25 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "Structural descriptor - identifies whether a structure is at equilibrium",
+    "description": "Differentiates structures with similar composition but different characteristics",
+    "allOf": [
+        {
+            "$ref": "file:../schemas/compound_specific.json"
+        }
+    ],
+    "properties": {
+        "name": {
+            "enum": [
+                "is_relaxed"
+            ]
+        },
+        "value": {
+            "description": "Identifies a equilibrium structure.",
+            "type": "boolean"
+        }
+    },
+    "required": [
+        "name",
+        "value"
+    ]
+}
diff --git a/schema/material/fingerprint/primary/local_environment.json b/schema/material/fingerprint/primary/local_environment.json
new file mode 100644
index 000000000..c13fbab72
--- /dev/null
+++ b/schema/material/fingerprint/primary/local_environment.json
@@ -0,0 +1,39 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "local environment around an atom schema",
+    "description": "local environment around each element defined by atom type each element is bonded to",
+    "allOf": [
+        {
+            "$ref": "file:../schemas/element_specific.json"
+        }
+    ],
+    "properties": {
+        "name": {
+            "enum": [
+                "local_environment"
+            ]
+        },
+        "elements": {
+            "items": {
+                "value": {
+                    "description": "atom symbol to which element is bonded to. X means non-bonded or bonded to any atom other than the ones in the list",
+                    "type": "array",
+                    "items":{
+                        "enum": [
+                            "H",
+                            "O",
+                            "S",
+                            "F",
+                            "Cl",
+                            "X"
+                        ]
+                    }
+                }
+            }
+        }
+    },
+    "required": [
+        "name",
+        "elements"
+    ]
+}
diff --git a/schema/material/fingerprint/primary/material_type.json b/schema/material/fingerprint/primary/material_type.json
new file mode 100644
index 000000000..17455d27c
--- /dev/null
+++ b/schema/material/fingerprint/primary/material_type.json
@@ -0,0 +1,31 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "Structural descriptor - type of material",
+    "description": "crystal or molecule or amorphous or polymer.",
+    "allOf": [
+        {
+            "$ref": "file:../schemas/compound_specific.json"
+        }
+    ],
+    "properties": {
+        "name": {
+            "enum": [
+                "material_type"
+            ]
+        },
+        "value": {
+            "description": "material type",
+            "type": "string",
+            "enum": [
+                "crystal",
+                "polymer",
+                "molecule",
+                "amorphous"
+            ]
+        }
+    },
+    "required": [
+        "name",
+        "value"
+    ]
+}
diff --git a/schema/material/fingerprint/primary/p_norms.json b/schema/material/fingerprint/primary/p_norms.json
new file mode 100644
index 000000000..25cadf602
--- /dev/null
+++ b/schema/material/fingerprint/primary/p_norms.json
@@ -0,0 +1,30 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "stoichiometric descriptor - p-norms schema",
+    "description": "values calculated using L-p norm upto p-dimensions",
+    "allOf": [
+        {
+            "$ref": "file:../schemas/compound_specific_array.json"
+        }
+    ],
+    "properties": {
+        "name": {
+            "enum": [
+                "p_norms"
+            ]
+        },
+        "data": {
+            "items": {
+                "name": {
+                    "description": "p-norms. Upto p99 allowed. Eg: p03",
+                    "type": "string",
+                    "pattern": "p[0-9]{2}"
+                }
+            }
+        }
+    },
+    "required": [
+        "name",
+        "data"
+    ]
+}
diff --git a/schema/material/fingerprint/primary/valence_orbital_occupancy.json b/schema/material/fingerprint/primary/valence_orbital_occupancy.json
new file mode 100644
index 000000000..cdb37bb49
--- /dev/null
+++ b/schema/material/fingerprint/primary/valence_orbital_occupancy.json
@@ -0,0 +1,35 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "electronic descriptor - valence orbital occupancy schema",
+    "description": "fraction-weighted average of the number of valance electrons in each orbital divided by total valence electrons",
+    "allOf": [
+        {
+            "$ref": "file:../schemas/compound_specific_array.json"
+        }
+    ],
+    "properties": {
+        "name": {
+            "enum": [
+                "valence_orbital_occupancy"
+            ]
+        },
+        "data": {
+            "items": {
+                "name": {
+                    "description": "valence orbital occupancy - https://www.nature.com/article-assets/npg/npjcompumats/2016/npjcompumats201628/extref/npjcompumats201628-s1.pdf",
+                    "type": "string",
+                    "enum": [
+                        "s",
+                        "p",
+                        "d",
+                        "f"
+                    ]
+                }
+            }
+        }
+    },
+    "required": [
+        "name",
+        "data"
+    ]
+}
diff --git a/schema/material/fingerprint/schemas/compound_specific.json b/schema/material/fingerprint/schemas/compound_specific.json
new file mode 100644
index 000000000..31447c516
--- /dev/null
+++ b/schema/material/fingerprint/schemas/compound_specific.json
@@ -0,0 +1,23 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "compound specific descriptors schema",
+    "description": "applicable for nominal/ordinal/numeric value types",
+    "properties": {
+        "name": {
+            "description": "name of the descriptor",
+            "type": "string"
+        },
+        "value": {
+            "description": "value of the descriptor",
+            "type": [
+                "string",
+                "number",
+                "boolean"
+            ]
+        }
+    },
+    "required": [
+        "name",
+        "value"
+    ]
+}
diff --git a/schema/material/fingerprint/schemas/compound_specific_array.json b/schema/material/fingerprint/schemas/compound_specific_array.json
new file mode 100644
index 000000000..eed9df8c0
--- /dev/null
+++ b/schema/material/fingerprint/schemas/compound_specific_array.json
@@ -0,0 +1,31 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "compound-specific descriptor array schema",
+    "description": "multiple elements related to compound-specific descriptor. Example: p-norms",
+    "properties": {
+        "name": {
+            "description": "name of the descriptor",
+            "type": "string"
+        },
+        "data": {
+            "description": "compound-specific descriptor data in an array",
+            "type": "array",
+            "items": {
+                "properties": {
+                    "name": {
+                        "description": "variable name",
+                        "type": "string"
+                    },
+                    "value": {
+                        "description": "the value for the corresponding elemental property",
+                        "type": "number"
+                    }
+                }
+            }
+        }
+    },
+    "required": [
+        "name",
+        "data"
+    ]
+}
diff --git a/schema/material/fingerprint/schemas/element_specific.json b/schema/material/fingerprint/schemas/element_specific.json
new file mode 100644
index 000000000..11e737b43
--- /dev/null
+++ b/schema/material/fingerprint/schemas/element_specific.json
@@ -0,0 +1,26 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "element specific descriptors schema",
+    "description": "applicable for nominal/ordinal/numeric value types",
+    "properties": {
+        "elements": {
+            "description": "elements in a material and corresponding descriptor value",
+            "type": "array",
+            "items": {
+                "properties": {
+                    "name": {
+                        "description": "element symbol. Eg: Si",
+                        "type": "string"
+                    },
+                    "value": {
+                        "description": "elemental property value",
+                        "type": ["string", "number", "array"]
+                    }
+                }
+            }
+        }
+    },
+    "required": [
+        "elements"
+    ]
+}
diff --git a/schema/material/structure/atomic_data.json b/schema/material/structure/atomic_data.json
index 4273721aa..7d6f0b9c1 100644
--- a/schema/material/structure/atomic_data.json
+++ b/schema/material/structure/atomic_data.json
@@ -4,46 +4,46 @@
     "description": "properties of atoms in arrays indexed by ids",
     "type": "object",
     "properties": {
-        "valenceElectrons": {
-            "description": "number of valence electrons",
+        "occurrence": {
+            "description": "occurrence of the element for fractional occupancy",
             "properties": {
                 "value": {
                     "$ref": "file:atomic_masses.json"
                 },
                 "name": {
                     "enum": [
-                        "valence_electrons"
+                        "occurrence"
                     ]
                 }
             }
         },
-        "charges": {
-            "description": "difference between total and valence electrons on atom",
+        "oxidationState": {
+            "description": "oxidation state of the element",
             "properties": {
                 "value": {
                     "$ref": "file:atomic_masses.json"
                 },
                 "name": {
                     "enum": [
-                        "charges"
-                    ]
-                },
-                "units": {
-                    "enum": [
-                        "electron charge"
+                        "oxidation_state"
                     ]
                 }
             }
         },
-        "radicals": {
-            "description": "number of unpaired electrons",
+        "charges": {
+            "description": "difference between total and valence electrons on atom",
             "properties": {
                 "value": {
                     "$ref": "file:atomic_masses.json"
                 },
                 "name": {
                     "enum": [
-                        "radicals"
+                        "charges"
+                    ]
+                },
+                "units": {
+                    "enum": [
+                        "electron charge"
                     ]
                 }
             }
diff --git a/schema/material/structure/atomic_elements.json b/schema/material/structure/atomic_elements.json
index e21e4c2e7..559381554 100644
--- a/schema/material/structure/atomic_elements.json
+++ b/schema/material/structure/atomic_elements.json
@@ -11,14 +11,6 @@
         "value": {
             "description": "atomic elements (eg Si, Ge)",
             "type": "string"
-        },
-        "occurrence": {
-            "description": "occurrence of the element for fractional occupancy",
-            "type": "number"
-        },
-        "oxidationState": {
-            "description": "oxidation state of the element",
-            "type": "integer"
         }
     }
 }
diff --git a/schema/material/units.json b/schema/material/units.json
new file mode 100644
index 000000000..339f0e8cb
--- /dev/null
+++ b/schema/material/units.json
@@ -0,0 +1,42 @@
+{
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "units schema",
+    "definitions": {
+        "length":{
+            "enum":[
+                "km",
+                "m",
+                "pm",
+                "nm",
+                "angstrom",
+                "a.u."
+            ]
+        },
+        "energy":{
+            "enum":[
+                "kJ/mol",
+                "eV",
+                "J/mol",
+                "hartree",
+                "cm-1",
+                "eV/atom"
+            ]
+        },
+        "volume": {
+            "enum": [
+                "cm^3",
+                "angstrom^3"
+            ]
+        },
+        "numberDensity":{
+            "enum": [
+                "1/angstrom^3"
+            ]
+        },
+        "density":{
+            "enum": [
+                "g/cm^3"
+            ]
+        }
+    }
+}
diff --git a/tests/validate.spec.js b/tests/validate.spec.js
index fd56d6f12..25410c7b8 100644
--- a/tests/validate.spec.js
+++ b/tests/validate.spec.js
@@ -42,7 +42,7 @@ function parseJSONInclude(dirpath, filename, isInclude) {
         json = fs.readFileSync(filepath, 'utf8'),
         d = JSON.parse(json);
     if (isInclude) {
-        if (! isInstance(d, "Object")) {
+        if (!isInstance(d, "Object")) {
             throw "The JSON file being included should always be a dict rather than a list";
         }
     }
@@ -103,7 +103,7 @@ function walkThoughToInclude(obj, dirpath) {
  * see walkSync docs for more info.
  */
 walkSync(schemasDir, function (dirPath, dirs, files) {
-    files.forEach(f=> {
+    files.forEach(f => {
         const filePath = path.join(dirPath, f);
         const dir = _.trimStart(dirPath.replace(schemasDir, ''), '/');
 
@@ -125,7 +125,7 @@ walkSync(schemasDir, function (dirPath, dirs, files) {
 });
 
 // generate id for each schema and replace $refs values by appropriate id
-schemas.forEach(schema=> {
+schemas.forEach(schema => {
     addIdProp(schema);
     replaceRefs(schema);
 });
@@ -159,9 +159,10 @@ function addIdProp(schema) {
     schema.id = schema.content.id;
 }
 
+
 var ajv = Ajv({
     allErrors: true,
-    schemas: schemas.map(schema=> schema.content)
+    schemas: schemas.map(schema => schema.content)
 });
 
 describe('ajv', function () {
@@ -182,7 +183,7 @@ describe('example', function () {
                 const validator = ajv.getSchema(schema.id);
                 const valid = validator(schema.example);
                 if (!valid) {
-                    console.log(JSON.stringify(schema.example))
+                    console.log(JSON.stringify(schema.example));
                     console.log(prettyjson.render(validator.errors));
                 }
                 chai.expect(valid).to.be.ok;