Dear all

I have a question about the calculation of pair potential of MEAM in LAMMPS

The implementation of MEAM is based on the paper of I. Huang, MSMSE, 3:615(1995), which gives the formulation about pair potential calculation as following

Phi_ij=[2*Eu-F_i(rho_j)-F_j(rho_i)]/Z_ij

But in lammps, it gives the pair potential like

Phi_ij=[2*Eu-F_i(rho_i)-F_j(rho_j)]/Z_ij

I firstly changed this and do the example for comparison. The SiC example showed some difference

And if looking up other literature, e.g., Baskes, MSMSE, 2:505(1994), the pair potential for like atoms is then given by

Phi_ii=2*[E_u-F_i(rho0_i/Z_i)]/Z_i

Then I tried to implement this in. The Ni example gave me same result compared to the original one but the error of losing atoms appeared in this case for SiC example.

Also, there are other pair potential calculations in some papers, i.e. Baskes, 75, 054106(2007)…

Is there some easy way to add the pair potential calculation in or actually they actually are same since it gives same result for some problem?

Thanks for your advice in advance

Best

Yi