Contact Number: The contact number of an amino acid residue in a protein structure is defined by the number of C(beta) atoms around the C(beta) atom of the given residue, a quantity similar to, but different from, solvent accessible surface area. from: http://www.ncbi.nlm.nih.gov ...
Software using PDB file HBPLUS http://www.ebi.ac.uk/thornton-srv/software/HBPLUS/ compute all possible van der Waals contacts and hydrogen bonds MOLMOL compute the relative solvent-accessible surface area of each amino acid from the protein structure. SCWRL http: ...