Subject: charge group information in psf file

From: "J. Zheng" <[email-masked]>
Date: Thu, 27 Feb 2003 18:08:13 -0800 (PST)

Dear CCLers:

  I have a basic question about protein structure file (psf) in CHARMM. In
psf file, the last section lists the charge group information. But I have
not figured out what relationship is among those atom index. It is very
straight forward to understand bonds, angle, dihedral, and improper atom
lists.

 here is a part of ALA residue PSF file.

      12 !NBOND: bonds
       2 1    3 1     4 1    7 5
       1 5   11 5     5 6    7 8
       7 9   7 10   11 13   11 12
.....
      3 0 !NGRP NST2
      0   2    0    6    1    0    10   2   0

 I don't undertand what those number stands for.

 I will appreciate for any hint or help.

 good day

 jie