I don't find an appropriate pair_style to use with cvff

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1

I’m trying to simulate a zeolite structure (MFI) with the cvff force field.

The equation to calculate nonbonded interactions for this force field is as follows:

E = Aij/r^12 - Bij/r^6
where Aij = sqrt( Ai * Aj )

Bij = sqrt( Bi * Bj )

Looking in lammps documentation I couldn’t find a pair style that uses this equation. The only that comes close is pair_style lj/cut:

E=4ε[(σ/r)¹²-(σ/r)⁶]

I’m looking for suggestions on how to handle this. Should I try to convert parameters to fit to the equation that lammps uses?

2

I'm trying to simulate a zeolite structure (MFI) with the cvff force
field.

The equation to calculate nonbonded interactions for this force field is
as follows:

E = Aij/r^12 - Bij/r^6
where Aij = sqrt( Ai * Aj )
            Bij = sqrt( Bi * Bj )

Looking in lammps documentation I couldn't find a pair style that uses
this equation. The only that comes close is pair_style lj/cut:

E=4ε[(σ/r)¹²-(σ/r)⁶]

I'm looking for suggestions on how to handle this. Should I try to convert
parameters to fit to the equation that lammps uses?

​they are the same equation, just different partitioning of the constants.
for as long as Ai, Aj, Bi, and Bj are != 0, you can convert between them.
this is middle-school level calculus.

axel.