diff --git a/example/material.json b/example/material.json
index efad29211..ef208b16a 100644
--- a/example/material.json
+++ b/example/material.json
@@ -48,11 +48,19 @@
             "value": 2.33
         },
         {
-            "name": "symmetry",
-            "spaceGroupSymbol": "Fd-3m",
+            "name": "symmetry_symbol_point_group",
+            "pointGroupSymmetry": "D*h",
             "tolerance": {
-                "units": "angstrom",
-                "value": 0.3
+                "value": 0.3,
+                "units": "angstrom"
+            }
+        },
+        {
+            "name": "symmetry_symbol_space_group",
+            "pointGroupSymmetry": "Fd-3m",
+            "tolerance": {
+                "value": 0.3,
+                "units": "angstrom"
             }
         },
         {
@@ -63,15 +71,7 @@
         {
             "element": "Si",
             "name": "elemental_ratio",
-            "value": 0.71
-        },
-        {
-            "name": "inchi",
-            "value": ""
-        },
-        {
-            "name": "inchi_key",
-            "value": ""
+            "value": 1.0
         }
     ],
     "exabyteId": "RKiswuxHKkF3uvLyA",
diff --git a/example/molecule.json b/example/molecule.json
new file mode 100644
index 000000000..efe5fe99d
--- /dev/null
+++ b/example/molecule.json
@@ -0,0 +1,121 @@
+{
+    "_id": "LCthJ6E2QabYCZqf3",
+    "basis": {
+        "coordinates": [
+            {
+                "id": 1,
+                "value": [
+                    2.500000,
+                    2.500000,
+                    2.833300
+                ]
+            },
+            {
+                "id": 2,
+                "value": [
+                    2.500000,
+                    1.250000,
+                    2.333300
+                ]
+            },
+            {
+                "id": 3,
+                "value": [
+                    2.500000,
+                    3.750000,
+                    2.333300
+                ]
+            }
+        ],
+        "elements": [
+            {
+                "id": 1,
+                "value": "S"
+            },
+            {
+                "id": 2,
+                "value": "H"
+            },
+            {
+                "id": 3,
+                "value": "H"
+            }
+        ],
+        "name": "basis",
+        "units": "cartesian"
+    },
+    "createdAt": "2016-04-03T05:25:37.430Z",
+    "creator": {
+        "...": "include(system/creator.json)"
+    },
+    "derivedProperties": [
+        {
+            "name": "symmetry_symbol_point_group",
+            "pointGroupSymmetry": "C2v",
+            "tolerance": {
+                "value": 0.3,
+                "units": "angstrom"
+            }
+        },
+        {
+            "name": "symmetry_symbol_space_group",
+            "pointGroupSymmetry": "Pmm2",
+            "tolerance": {
+                "value": 0.3,
+                "units": "angstrom"
+            }
+        },
+        {
+            "degree": 10,
+            "name": "p-norm",
+            "value": 0.6667
+        },
+        {
+            "element": "S",
+            "name": "elemental_ratio",
+            "value": 0.333333
+        },
+        {
+            "element": "H",
+            "name": "elemental_ratio",
+            "value": 0.666667
+        },
+        {
+            "name": "inchi",
+            "value": "1S/H2S/h1H2"
+        },
+        {
+            "name": "inchi_key",
+            "value": "RWSOTUBLDIXVET-UHFFFAOYSA-N"
+        },
+        {
+            "name": "molecular_weight",
+            "value": 33.988,
+            "units":"g/mol"
+        }
+    ],
+    "exabyteId": "RKiswuxHKkF3uvLyA",
+    "formula": "H2S",
+    "hash": "2ac7003120b82283f6199386d3ec2a3f",
+    "isDefault": false,
+    "isNonPeriodic": true,
+    "lattice": {
+        "a": 5.0,
+        "alpha": 90.0,
+        "b": 5.0,
+        "beta": 90.0,
+        "c": 5.0,
+        "gamma": 90.0,
+        "name": "lattice",
+        "type": "CUB"
+    },
+    "name": "H2S-Non-Periodic",
+    "owner": {
+        "...": "include(system/owner.json)"
+    },
+    "scaledHash": "659b47a160a06035fd8276ddcedbfac4",
+    "schemaVersion": "0.2.0",
+    "slug": "hydrogen-sulfide",
+    "unitCellFormula": "H2S",
+    "updatedAt": "2016-04-04T17:58:42.867Z"
+}
diff --git a/example/properties_directory/structural/molecular_weight.json b/example/properties_directory/structural/molecular_weight.json
new file mode 100644
index 000000000..da08b8cde
--- /dev/null
+++ b/example/properties_directory/structural/molecular_weight.json
@@ -0,0 +1,5 @@
+{
+    "name": "molecular_weight",
+    "value": 16.0313,
+    "units": "g/mol"
+}
diff --git a/example/properties_directory/structural/symmetry.json b/example/properties_directory/structural/symmetry.json
deleted file mode 100644
index 7e8e6be76..000000000
--- a/example/properties_directory/structural/symmetry.json
+++ /dev/null
@@ -1,9 +0,0 @@
-{
-    "name": "symmetry",
-    "pointGroupSymbol": "C2v",
-    "spaceGroupSymbol": "Fd-3m",
-    "tolerance": {
-        "units": "angstrom",
-        "value": 0.3
-    }
-}
diff --git a/example/properties_directory/structural/symmetry_symbol_point_group.json b/example/properties_directory/structural/symmetry_symbol_point_group.json
new file mode 100644
index 000000000..dcd77214f
--- /dev/null
+++ b/example/properties_directory/structural/symmetry_symbol_point_group.json
@@ -0,0 +1,8 @@
+{
+    "name": "symmetry_symbol_point_group",
+    "value": "C2v",
+    "tolerance": {
+        "value": 0.3,
+        "units":"angstrom"
+    }
+}
diff --git a/example/properties_directory/structural/symmetry_symbol_space_group.json b/example/properties_directory/structural/symmetry_symbol_space_group.json
new file mode 100644
index 000000000..00c6f573c
--- /dev/null
+++ b/example/properties_directory/structural/symmetry_symbol_space_group.json
@@ -0,0 +1,8 @@
+{
+    "name": "symmetry_symbol_space_group",
+    "value": "Fd-3m",
+    "tolerance": {
+        "value": 0.3,
+        "units": "angstrom"
+    }
+}
diff --git a/manifest/properties.yaml b/manifest/properties.yaml
index a339ea013..004a7d21f 100644
--- a/manifest/properties.yaml
+++ b/manifest/properties.yaml
@@ -205,10 +205,15 @@ volume:
     units: angstrom^3
   schemaId: properties-directory-structural-volume
 
-symmetry:
+symmetry_symbol_point_group:
   defaults:
     units: angstrom
-  schemaId: properties-directory-structural-symmetry
+  schemaId: properties-directory-structural-symmetry-symbol-point-group
+
+symmetry_symbol_space_group:
+  defaults:
+    units: angstrom
+  schemaId: properties-directory-structural-symmetry-symbol-space-group
 
 elemental_ratio:
   schemaId: properties-directory-structural-elemental-ratio
@@ -235,5 +240,11 @@ inchi:
 inchi_key:
   schemaId: properties-directory-structural-inchi_key
 
+molecular_weight:
+  schemaId: properties-directory-structural-molecular-weight
+
 material:
   schemaId: material
+
+molecule:
+  schemaId: molecule
diff --git a/schema/molecule.json b/schema/molecule.json
new file mode 100644
index 000000000..ec909c08d
--- /dev/null
+++ b/schema/molecule.json
@@ -0,0 +1,11 @@
+{
+    "schemaId": "molecule",
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "molecule schema",
+    "allOf": [
+        {
+            "description": "material schema",
+            "$ref": "material.json"
+        }
+    ]
+}
diff --git a/schema/properties_directory/derived_properties.json b/schema/properties_directory/derived_properties.json
index 1417b5293..a062fb61c 100644
--- a/schema/properties_directory/derived_properties.json
+++ b/schema/properties_directory/derived_properties.json
@@ -12,7 +12,10 @@
                 "$ref": "structural/density.json"
             },
             {
-                "$ref": "structural/symmetry.json"
+                "$ref": "structural/symmetry_symbol_point_group.json"
+            },
+            {
+                "ref": "structural/symmetry_symbol_space_group.json"
             },
             {
                 "$ref": "structural/elemental_ratio.json"
@@ -25,6 +28,9 @@
             },
             {
                 "$ref": "structural/inchi_key.json"
+            },
+            {
+                "$ref": "structural/molecular_weight.json"
             }
         ]
     }
diff --git a/schema/properties_directory/structural/molecular_weight.json b/schema/properties_directory/structural/molecular_weight.json
new file mode 100644
index 000000000..831108521
--- /dev/null
+++ b/schema/properties_directory/structural/molecular_weight.json
@@ -0,0 +1,23 @@
+{
+    "schemaId": "properties-directory-structural-molecular-weight",
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "molecular-weight schema",
+    "allOf": [
+        {
+            "$ref": "../../core/primitive/scalar.json"
+        }
+    ],
+    "properties": {
+        "name": {
+            "enum": [
+                "molecular_weight"
+            ]
+        },
+        "units": {
+            "enum": [
+                "g/mol"
+            ]
+        }
+    }
+}
+
diff --git a/schema/properties_directory/structural/symmetry.json b/schema/properties_directory/structural/symmetry_symbol_point_group.json
similarity index 57%
rename from schema/properties_directory/structural/symmetry.json
rename to schema/properties_directory/structural/symmetry_symbol_point_group.json
index f2f39324a..f46b5589c 100644
--- a/schema/properties_directory/structural/symmetry.json
+++ b/schema/properties_directory/structural/symmetry_symbol_point_group.json
@@ -1,15 +1,17 @@
 {
-    "schemaId": "properties-directory-structural-symmetry",
+    "schemaId": "properties-directory-structural-symmetry-symbol-point-group",
     "$schema": "http://json-schema.org/draft-04/schema#",
-    "title": "symmetry schema",
+    "title": "symmetry symbol point group schema",
+    "allOf": [
+        {
+            "$ref": "../../core/primitive/string.json"
+        }
+    ],
     "properties": {
-        "pointGroupSymbol": {
-            "description": "point group symbol in Schoenflies notation",
-            "type": "string"
-        },
-        "spaceGroupSymbol": {
-            "description": "space group symbol in Hermann\u2013Mauguin notation",
-            "type": "string"
+        "name": {
+            "enum": [
+                "symmetry_symbol_point_group"
+            ]
         },
         "tolerance": {
             "description": "tolerance used for symmetry calculation",
@@ -25,11 +27,6 @@
                     ]
                 }
             }
-        },
-        "name": {
-            "enum": [
-                "symmetry"
-            ]
         }
     }
 }
diff --git a/schema/properties_directory/structural/symmetry_symbol_space_group.json b/schema/properties_directory/structural/symmetry_symbol_space_group.json
new file mode 100644
index 000000000..45c2b7cab
--- /dev/null
+++ b/schema/properties_directory/structural/symmetry_symbol_space_group.json
@@ -0,0 +1,32 @@
+{
+    "schemaId": "properties-directory-structural-symmetry-symbol-space-group",
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "title": "symmetry symbol space group schema",
+    "allOf": [
+        {
+            "$ref": "../../core/primitive/string.json"
+        }
+    ],
+    "properties": {
+        "name": {
+            "enum": [
+                "symmetry_symbol_space_group"
+            ]
+        },
+        "tolerance": {
+            "description": "tolerance used for symmetry calculation",
+            "allOf": [
+                {
+                    "$ref": "../../core/primitive/scalar.json"
+                }
+            ],
+            "properties": {
+                "units": {
+                    "enum": [
+                        "angstrom"
+                    ]
+                }
+            }
+        }
+    }
+}