Usage:
split [ model_number(s) ] [ chains ] [ ligands ] [ connected ] [ atoms atom-spec ]_n

The split command partitions a molecule model into separate submodels, by default according to chain. The model_number(s) argument can be one or more model numbers or ranges separated by commas and preceded by #. If no models are specified, all molecule models will be affected.

How to split can be indicated with one or more of the following:

• chains - by chain ID
• ligands - each ligand in a separate submodel, the remaining atoms in another
• connected - into covalently bonded sets of atoms
• atoms  atom-spec  - can be used multiple times in the same command, for example:

  split #0 atoms :1-100 atoms :101-150 atoms :151-200

  ... to place each set of specified atoms, as well as the set of unspecified atoms, in a separate submodel.

Placing parts of a model in separate submodels allows for more independent control. For example, using the Model Panel, each can be activated/deactivated for motion or hidden/shown at the model level (without changing atomic display settings) independent of the others.

There is no way to undo this operation except by reopening the original structure.

See also: combine, surfcat, select, the accelerator Sc, the Model Panel, surface calculation failures and workarounds