Issue reading PDB file for non-X-ray PDB (CRYST1 header)

[maurobedoya]

PDB files exported with VMD that do not have cell size information (eg. vacuum simulations), throw the following error:

Error: Invalid size
Unhandled exception: Invalid size (Chem::ParseException)

The error occurs with a header of this type: CRYST1 0.000 0.000 0.000 90.00 90.00 90.00 P 1 1