Hello,
I am working with a system that uses pair style yukawa potential as well as a LJ/cut.
I have been doing some comparisons with the another MD program and found that my simulations in LAMMPS were slightly higher in total energy and narrowed down the problem to the yukawa potential. When I compute the yukawa pair potential energy in both MD programs I get 0 for lammps and the in the other a value which is the difference between the total energies in the two different programs. I have not encountered this problem before with lammps as I ran similar simulations before in which the yukawa potential energy was non-zero which compared to the other MD simulation quite well. The difference between earlier simulations were that I used a molecule file in one and in the newer ones I am using a data file. The two instances follow similar formats in whichI I:
read_data or molecule
pair_style hybdrid/overlay lj/cut args…..
pair_coeff 1 1 lj/cut …..
……………………….
pair_coeff 1 1 yukawa ….
………………………….
neigh_modify exclude molecule all
pair_modify shift yes
………...fixes and outputs……………
I’m not quite sure for the difference in why one way(using molecule file) accounts for the yukawa and the other(data file) does not.
I am using the LAMMPS (10 Feb 2015) version.
Any insight would be great,
Michael Goytia
Graduate Student
University of Utah Chemistry Department