force field for replica exchange with NAMD

From: Xiang Yu (
Date: Wed Oct 27 2010 - 23:06:32 CDT

Hello all,

NAMD gives a replica exchange example. The example uses alain.params which is modified from Charmm19 force field. I want to do REMD simulation with Charmm27 force field. I generate a force field with the parameters of bond, angle, dihe, impr and nonbonded directly coming from Charmm27. But I do not know how to put CMAP parameters into this modified force field so it can be read correctly.
I try to run REMD simulation with the modified force field which misses CMAP part, an error "FATAL ERROR: CAN"T FIND CROSSTERM PARAMETERS FOR C NH1 CT1 C NH1" will quickly comes out. So could anyone with experience of REMD tell me how to add CMAP into the force field for REMD, or how to skip CMAP correction during simulation?

Thank you,


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