Write saves the molecule model in model_number (not preceded by #) as a PDB file named filename. If filename is omitted, a dialog for specifying the name and location will appear. Only atomic coordinates are saved; atomic display status, color, and radius are not included. The write command does not work for non-molecule models (surfaces, VRML models, etc.). To save multiple models at once, use the Save PDB Dialog instead.
The relative option specifies that the coordinates written out should be relative to the untransformed coordinates of model n; otherwise, the coordinates will be written as currently transformed. The relative option is useful for preserving the spatial relationship between models. For example, if model 1 has been matched or docked to model 0, saving 1 relative to 0 results in the models being matched or docked in the same way when the model 0 file (original) and the model 1 file (saved relative to 0) are reopened.
The trajectory option specifies that if the model contains a trajectory, all frames should be written out. In this context, "all frames" means all frames that have been viewed with Movie. Otherwise, only the current frame will be written out.
See also: pdbrun, save, the Save PDB Dialog