Chimera can read molecular structures from formatted Gaussian checkpoint files. This file type is indicated by the filename suffix .fchk or by using prefix:filename in the command line, where prefix is fchk or gaussian.
Only the Atomic numbers and Current cartesian coordinates sections of the file are read; other sections are ignored and may be deleted. All atoms are placed in a single residue named UNK, and the atoms are named by element and the number of atoms of that element encountered so far. Coordinates expressed in bohrs are converted into angstroms.