AMBER: About the creation of 1-4 pairs in AMBER program

From: J. Zhang <>
Date: Mon, 4 Dec 2006 10:17:2 +0800

Dear AMBER users,

I want to know how the 1-4 pairlist is created in the AMBER program. By tracing the code,
I know that it is created by checking the dihedral interaction list. The program
      i3 = ip(n)
      j3 = jp(n)
      k3 = iabs(kp(n))
      l3 = iabs(lp(n))
      ic0 = icp(n)
      f = fmn(ic0)
      k = kp(n)
      l = lp(n)
      if( k>0 .and. l>0 .and f>0.d0 ... ) then
        add to list...
my question is: what is the fmn() array? is it related to extra-point? if I am using
the ff03 force field, can I ingored it safely?

Thank you very much!

J. Zhang, Dr.
Institute of Biophysics
Nanjing University
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Received on Wed Dec 06 2006 - 06:07:20 PST
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