problems in new pair_style for SiC (Vashishta et al.)

Hi Aidan or any other LAMMPS users,

I have created a new pair style named pair_vashishta for SiC, which is based on the following article:

P. Vashishta, R. K. Kalia, A. Nakano, and J. P. Rino, “Interaction potential for silicon carbide: A molecular dynamics study of elastic constants and vibrational density of states for crystalline and amorphous silicon carbide,” Journal of Applied Physics, vol. 101, no. 10, pp. 103515–103515–12, May 2007.

The format of this potential is similar to that of Stillinger-Weber, therefore the pair_vashishta is adapted from the pair_sw. The mainly changed sections are:
setup() {},
twobody(){} and

The new pair style has been compiled succeeded, but the test results looks unreasonable because the volume of the systems exploded and the energy per atom was not close to the one given in the literature mentioned above. I have checked the force and potetial expressions and the source file again and again. But I couldn’t find any mistake probably because my level of the MD knowledge is poor.

I attached the source files(.cpp and .h) ,the potential parameters file(SiC.vashishta), the input file(in.vashishta), read_data file(data.3CSiC) , the log file(log.lammps) and the reference article(.pdf). In addition, I run the LAMMPS(11 sep 2015) on a 64bit ubuntu OS.

Any advice is welcome.

Best regards.

Guangpeng Yan


SiC.vashishta (2.05 KB)

data.3CSiC (16.6 KB)

in.vashishta (1.09 KB)

log.lammps (435 KB)

pair_vashishta.cpp (18.5 KB)

pair_vashishta.h (3.6 KB)