I want to edit the screening function used in MEAM. LAMMPS has hard coded functional form as [1-(1-x)^4]^2. I want to change it to [1-(1-x)^6]^2. I did go through "meam_dens_init.F" file in the lib/meam/ directory and made changes in "fcut" and "dfcut" subroutines accordingly. Are there any other palces, I need to make changes?
I think those are the only places that change needs to be made, but you should also be aware that the fcut and dfcut subroutines are used not just the for screening function as it transitions between Cmin and Cmax, but also the for the smooth cutoff function on a pair of atoms as the interatomic distance approaches the cutoff radius (the function controlled by the rc and delr parameters in the input file). If it's not your intent to change both of these cutoffs, you may need to introduce a new pair of subroutines and apply them only for the screening function.
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I did not consider that. I guess, I will introduce a new subroutines.