# Using hybrid potential

I want to use a potential joined with ZBL and polynomial in LAMMPS. The potential is given by

F®=ZBL r<=r1;

F®= p5r^5+p4r4^4+p3r^3+p2r^2+p1*r+p0 r1<=r<r2

F®=(a+b/r)e^(-cr)*Fc® r=>r2

Where Fc® is a cut-off function, given by

Fc®=1 r<=rc-rd

Fc®=0.5*(1-sin(Pi*(r-rc)/2*rd)) |rc-r|<=rd

Fc®=0 r=>rc+rd

I want to know is there a suitable pair_style to describe the polynomial and the long-range part of potential? or I could only use the pair_style table to fit the potential into LAMMPS.

Thanks

Yi YU

I want to use a potential joined with ZBL and polynomial in LAMMPS. The
potential is given by

F(r)=ZBL
r<=r1;

F(r)= p5*r^5+p4*r4^4+p3*r^3+p2*r^2+p1*r+p0 r1<=r<r2

F(r)=(a+b/r)*e^(-c*r)*Fc(r)
r=>r2

Where Fc(r) is a cut-off function, given by

Fc(r)=1
r<=rc-rd

Fc(r)=0.5*(1-sin(Pi*(r-rc)/2*rd))
>rc-r|<=rd

Fc(r)=0
r=>rc+rd

I want to know is there a suitable pair_style to describe the polynomial and
the long-range part of potential?

to the best of my knowledge such a potential doesn't exist.

or I could only use the pair_style table to fit the potential into LAMMPS.

that is indeed the only way to introduce pairwise additive potentials
that are not otherwise programmed.

axel.