{
  "props": {
    "element_name": {
      "type": "String",
      "trim": true,
      "_m_category": "element name",
      "index": true
    },
    "element_symbol": {
      "type": "String",
      "trim": true,
      "_m_category": "element symbol",
      "index": true
    },
    "atomic_weight": {
      "type": "String",
      "trim": true,
      "_m_category": "atomic weight"
    },
    "element_number": {
      "type": "Number",
      "trim": true,
      "_m_category": "element number",
      "index": true
    },
    "_synonyms" :[
      { "category" : {
      "type": "String",
      "trim": true,
      "index": false
        },
      "fact" : {
      "type": "String",
      "trim": true,
      "index": false
      },
      "synonyms" : [
         {
      "type": "String",
      "trim": true,
      "index" : false
      }
      ]}
    ]
  },
  "index": {
    "element_name": "text",
    "element_number": "text"
  }
}