BaseChkptMol:
  superclass: BaseDataClass
  doc: | 
     Base class for checkpointed molecules.
     Not to be used directly. All times are in seconds.
  items:
  - name: id
    type: int
  - name: species
    type: Species*
  - name: diffusion_time 
    type: float     
  - name: birthday 
    type: float     
  - name: flags 
    type: int
  - name: unimol_rxn_time 
    type: float
    default: unset     

ChkptVolMol:
  superclass: BaseChkptMol
  doc: | 
     Class representing a checkpointed volume molecule.
     Not to be used directly.
  items:
  - name: pos
    type: Vec3

ChkptSurfMol:
  superclass: BaseChkptMol
  doc: | 
     Class representing a checkpointed surface molecule.
     Not to be used directly.
  items:
  - name: pos
    type: Vec2
  - name: orientation
    type: Orientation
  - name: geometry_object
    type: GeometryObject*
  - name: wall_index
    type: int
  - name: grid_tile_index
    type: int

RngState:
  superclass: BaseDataClass
  doc: Internal checkpointing structure holding state of the random number generator.
  items:
  - name: randcnt
    type: uint64
  - name: aa
    type: uint64
  - name: bb
    type: uint64
  - name: cc
    type: uint64
  - name: randslr
    type: List[uint64]
    doc: Must contain RNG_SIZE items.
  - name: mm
    type: List[uint64]
    doc: Must contain RNG_SIZE items.
  - name: rngblocks
    type: uint64
    doc: Must contain RNG_SIZE items.