I think that the first term of EAM (density function) will be influenced by

spline ZBL to the pairwise portion of EAM. So, modifying the form of density

function should be taken into account when we combine the ZBL with EAM. But I'm

not confirm that. Does someone have comments.

I don't think the idea to replace the tabulation of EAM that Steve mentioned

is a good method, though many people might have done EAM-ZBL hybrid in that

i disagree.

way. My concern is that spline the pair potential actually can avoid

overlap, but since the force is calculated by the derivative of potential

and considering that the potential formulas of EAM and ZBL are different,

the force calculated with the newly tabulated EAM would be different from

the force calculated with ZBL by the same value of potential and also

different from the real circumstance we expect.To fit a new formula around the overlap point, and implement it in the

source code of lammps seems more reasonable for me.However, I'm also just new to the potential discipline, please correct me if

there is anything wrong with me.

i don't know if there is anything wrong with you (i hope not), but

your concern is not valid.

when you tabulate a potential and then interpolate it with a spline

function, you will get a smooth interpolation that is a continuous

function with a continuous derivative function as well. this is by

construction. of course there can be artifacts if there is a

significant change in the potential at the transition point, but for

as long as you shift one of the potentials to have the same value as

the other (like steve mentioned), this will be minimal and should not

be a big concern. you should make an experiment and plot the resulting

function yourself. LAMMPS can help you to do that experiment without

having to write code yourself through using the pair_write command,

that writes out pairwise potentials, and the pair table style that

supports reading a tabulated potential and resplining them to

different grids.

axel.