[gmx-users] How to create S-S bond

[kinshuk at chem.iitb.ac.in]

Dear sir,
  I want to create S-S bond between two cys in a peptide chain
irrespective of
 the conformation of the peptide. I tried this using an option -ss as flag
in pdb2gmx but it failed to create S-S bond. since, S-S ditance was more
in free cysSH cysSH, but i want to bring them together to form S-S bond.
How  could i do this?