About tersoff potential entry

LAMMPS LAMMPS Mailing List Mirror
1

Hi, Axel and Steve:

Thanks for your kindly reply for my former question about the error originated from the combination of two tersoff/zbl lines. So I begin to

make my own tersoff potential file now.

In order to get a zbl potential, I just turned off the X_ij*B and A coefficient. At the same time, I increased the ZBLcut and ZBLexpscale to

minimize the effect of the fermi−like function in the original tersoff/zbl potential. However, I realized that the output energy still depended on the

choice of R and D even when I set the X_ij*B and A equal to zero. I am confused about this as the manual says that the cutoff distance (R+D) is

only for the tersoff part. So what can I do if I want a pure zbl potential file?

Thank you very much!

2011-11-25

2

Aidan may be able to answer this. He knows the
format of the Tersoff potential files better than me.

Steve

3

First of all, you are doing something that the original code was not
intended for, so you should be very careful. It would be best to create a
new pair style based on PairTersoff and PairTersoffSBL classes.

More specifically, the dependence on R+D occurs because this is the cutoff
that LAMMPS uses for neighbor lists. If your ZBL potential extended beyond
R+D, you will see a dependence on R+D.