Format specification can be found at: http://instinct.v24.uthscsa.edu/~hincklab/html/soft_packs/msi_docs/insight980/formats980/File_Formats_1998.html#484257
Read-only
This plugin is used only to read files. VMD does not currently support
writing this file type.
TODO:
The current code reads the file *four* times -- once on open, once
to read the structure, and twice to read the bonds. Perhaps these could
be consolidated, e.g. by counting the bonds and populating the hash
tables during open or read_structure.