Hi everyone,

I certainly hope i’m using this mailing list correctly! I’m freshly new to LAMMPS, so apologizes if this is a trivial question. I was wondering if it is possible to manually change the force equation that LAMMPS is using when using EAM.

In EAM, the force felt between neighbors is the following:

Force =

- sum [ ( F_i(Rho) )’ * (Rho_®j)’ +

( F_j(Rho) )’ * ( Rho_i( r ) )’ +

( Phi_ij( r ) )’ ] * r^

In charge density corrected EAM, the force needs to be (b and c are constants):

Force =

- sum [ ( F_i(Rho + B*|grad(Rho_i)|^2 ) + c
*Rho_i)’ * (Rho_j)’ +*|grad(Rho_j)|^2 ) + c

( F_j(Rho + B*Rho_j)’ * (Rho_i)’ +*Rho_i)’ ] * r^

(Phi_ij - 2c

I was reading the documentation and it states i should not just go and make changes to LAMMPS. How would i go about making this one change? Would it be best to make a completely new pairstyle as opposed to editing the EAM one?

Many thanks,

Michael