namd question in parameter conversion

From: Liqun Zhang (
Date: Wed Jan 18 2012 - 10:27:12 CST

Dear namd users:

I like to convert the system from charmm into namd. I used following
command in charmm:

nbonds atom cdie cutnb 16.0 ctofnb 12.0 ctonnb 10.0 bycb -
    wmin 1.0 eps 1.0 inbfrq -1 cutim 16.0 imgfrq -1 -
    ewald pme order 6 spline kappa 0.34 fftx @fftx ffty @ffty fftz @fftz

which means that i used the cufoff of van der waal interaction at 16 A, the
switching value is 12 A, and the smoothing function begins at 10 A.

In the namd simulations, I like to use the same kind of parameters in NPT
simulation, I have following content in the input file:

# Force-Field Parameters
exclude scaled1-4
1-4scaling 1.0
cutoff 16.
switching on
switchdist 12.
pairlistdist 14

here, I am not sure how to fill the pairlistdist value based on charmm
parameters, and I believe the cutoff setting, switchdist setting should be
correct. Can somebody help me on this? Thank you very much.

Kindly regards,

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