Trajectory schema
=================
A full description of the overall Trajectory model.

Required Keys
-------------

The following properties are required for the Trajectory specification.
   +-------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------+----------------------------------------------------------------------------------+
   | Key Name                                                                                        | Description                                                                                                              | Field Type                                                                       |
   +=================================================================================================+==========================================================================================================================+==================================================================================+
   | timestep                                                                                        | No description provided.                                                                                                 | number                                                                           |
   +-------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------+----------------------------------------------------------------------------------+

Optional Keys
-------------

The following keys are optional for the Trajectory specification.
   +-------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------+----------------------------------------------------------------------------------+
   | Key Name                                                                                        | Description                                                                                                              | Field Type                                                                       |
   +=================================================================================================+==========================================================================================================================+==================================================================================+
   | extras                                                                                          | Additional information to bundle with this object. Use for schema development and scratch space.                         | object                                                                           |
   +-------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------+----------------------------------------------------------------------------------+
   | forces                                                                                          | An ordered (natoms*ndim*nframes,) array for XYZ atomic forces. Default unit is kJ/mol*angstrom.                          | array[number]                                                                    |
   +-------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------+----------------------------------------------------------------------------------+
   | forces_units                                                                                    | Units for atomic forces. Defaults to kJ/mol*angstrom.                                                                    | string                                                                           |
   +-------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------+----------------------------------------------------------------------------------+
   | geometry                                                                                        | An ordered (natom*ndim*nframes,) array for XYZ atomic coordinates. Default unit is Angstrom. Storage is sequential in    | array[number]                                                                    |
   |                                                                                                 | each dimension: [    x1o,...,xno, y1o,...,yno, z1o,...,zno, # 1st frame     ...,    x1f,...,xnf, y1f,...,ynf,            |                                                                                  |
   |                                                                                                 | z1f,...,znf,# final frame  ]                                                                                             |                                                                                  |
   +-------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------+----------------------------------------------------------------------------------+
   | geometry_units                                                                                  | Units for atomic geometry. Defaults to Angstroms.                                                                        | string                                                                           |
   +-------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------+----------------------------------------------------------------------------------+
   | name                                                                                            | Common or human-readable name to assign to this molecule. This field can be arbitrary; see ``identifiers`` for well-     | string                                                                           |
   |                                                                                                 | defined labels.                                                                                                          |                                                                                  |
   +-------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------+----------------------------------------------------------------------------------+
   | ndim                                                                                            | Number of spatial dimensions.                                                                                            | integer                                                                          |
   +-------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------+----------------------------------------------------------------------------------+
   | nframes                                                                                         | Number of frames.                                                                                                        | integer                                                                          |
   +-------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------+----------------------------------------------------------------------------------+
   | provenance                                                                                      | The provenance information about how this object (and its attributes) were generated, provided, and manipulated.         | object                                                                           |
   +-------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------+----------------------------------------------------------------------------------+
   | schema_name                                                                                     | The MMSchema specification to which this model conforms. Explicitly fixed as mmschema_trajectory.                        | string                                                                           |
   +-------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------+----------------------------------------------------------------------------------+
   | schema_version                                                                                  | The version number of ``schema_name`` to which this model conforms.                                                      | integer                                                                          |
   +-------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------+----------------------------------------------------------------------------------+
   | timestep_units                                                                                  | Timestep size units. Defaults to femtoseconds.                                                                           | string                                                                           |
   +-------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------+----------------------------------------------------------------------------------+
   | top                                                                                             | No description provided.                                                                                                 | array[#/definitions/Molecule]                                                    |
   +-------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------+----------------------------------------------------------------------------------+
   | velocities                                                                                      | An ordered (natoms*ndim*nframes,) array for XYZ atomic velocities. Default unit is Angstroms/femtoseconds.               | array[number]                                                                    |
   +-------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------+----------------------------------------------------------------------------------+
   | velocities_units                                                                                | Units for atomic velocities. Defaults to Angstroms/femtoseconds.                                                         | string                                                                           |
   +-------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------------------------------------+----------------------------------------------------------------------------------+