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:
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