namd CG minimization error: unable to find angle parameters for nxg nxx nxg

From: Francesco Pietra (
Date: Thu Dec 10 2009 - 10:27:13 CST

I am trying to minimize at const vol a CG system
protein-popcbilayer-water with protein and bilayer restrained. After
adjusting the conf file on the basis of errors messages, I am getting
an error "unable to find angle parameters for nxg nxx nxg" which I
could not remedy although I have followed the thread with same error.

The conf file

# Input
paraTypeCharmm on
parameters /workingdir/rbcg-2007.par

means that the par file is in the working dir and it contains the
requested parameters. Is rbcg-2007.par not enough? In particular, how
to give parameters for the POPC lipid, which are not comprised in that
par file?

But I was suspicious that the above setting of parameters is incorrect
because if I modify

# Force-Field Parameters
exclude scaled1-4
1-4scaling 1.0
cutoff 12.
switching on
switchdist 10.
pairlistdist 13.5

to scaling 1-2 (as I have seen in a thread for CG), I get "Error: 1-2
scaling". Which seems to me to imply that the procedure is assuming -
from the above input -an all-atoms system.

Thanks for help

francesco pietra

This archive was generated by hypermail 2.1.6 : Wed Feb 29 2012 - 15:53:35 CST