[lammps-users] help pair_style

Hello,

I am new with lammps. I am traing to simulate the fusion of an oxide metal. I want to use the following potential:

u (r) = A (r) + B (r)

where

A * exp ((sigma - r) / rho) - C / r ^ 6 - D / r ^ 8
B (r) = C 'qiqj / (epsilon * r)

I try to include both kinds of potentials (born/coul/long + coul/cut) in the pot.mod file but it does not work. How can I proceed?

pot.mod file

pair_style born/coul/long 8
dielectric 1.0
pair_coeff 1 1 0.18 0.16000 0.4400 10.0 20.0

pair_style coul/cut 8
pair_coeff * *

Thanks

if you issue a pair_style command multiple times, then then second will replace the former.
if you want to use multiple pair styles at the same time, you need to use either pair style hybrid (which allows different styles for pairs of atom types)
or hybrid/overlay to sum contributions from multiple pair styles.

but this is not required here. just using born/coul/long should suffice as it includes both the A® and B® parts of your potential.

axel.

Thanks very much

Mauricio Rodríguez
Centro Universitario Regional del Este (CURE) - Rocha
Universidad de la República - Uruguay
Tel: (598) 4472 7001 int 491 o 385
email: [ mailto:[email protected] | [email protected] ]