I am unfamiliar with the modeling procedures in Lammps.  I am concerned by
the use of '0.0' as a weighting factor.  The true default weighting factors
are 1.0, 1.0, 0.5 and 1.0, 1.0, 0.8333.  That is, 1-2 and 1-3 interactions
are not changed from their entries in the parameter files, and, thus are
effectively multiplied by 1.0.  Multiplying by zero would have undesirable
effects, but perhaps the Lammps format responds appropriately to such a

For GLYCAM parameters, the 1-4 weights should be 1.0 as well.  These are
indicated in the parameter file.  To see what I mean, search the file at
the following link for the terms SCEE and SCNB:

On Wed, Jul 26, 2017 at 1:52 PM, Naveen Kumar Vasudevan <
[log in to unmask]> wrote:

> Hi all,
> I am simulating CNC using GLYCAM in Lammps, where I use the special_bonds
> command to define the weighing factors for  1-2,1-3,1-4 atom's  LJ
> interaction and Coulombic interactions.
> I am using AMBER's weighing factor values of 0.0, 0.0, 0.5 (LJ
> interactions) and 0.0, 0.0, 0.8333 (Coulombic) for 1-2,1-3,1-4 interactions
> respectively.
> Are these weighing factors fine for GLYCAM as well.
> Thank you,
> Regards
> Naveen

:-) Lachele
Lachele Foley
Athens, GA USA