interface reads coordinate files and writes files of inter-chain residue-residue contact data.
Here is a sample session with interface:
Name of protein coordinate file for input (EMBL format).
Name of data file with Van der Waals radii.
Threshold contact distance.
Name of contact file for output.
Name of log file for the build.
If any two atoms from two different residues are at least this distance apart, no futher inter-atomic contacts are checked for for that residue pair. This speeds up the calculation considerably.