[lammps-users] Re-Re: Pair-Angle-Bond coeff in data file

Hi,

So I've modified my data file with this for my Pair Coeff section:

Pair Coeffs

1*2 0.0 0.0 # eta, sigma, LJ cutoff
1 0.1550 3.1536
2 0.0 0.0
But I get a message error : Expected integer parameter in input script or data file (../read_data.cpp:2061)
It is because of the asterisk I guess but I don't see why it generates an error or what syntax to use... I've tried to follow the doc for the coefficient arguments inthe pair_coeff command info

Hi,

So I’ve modified my data file with this for my Pair Coeff section:

Pair Coeffs

1*2 0.0 0.0 # eta, sigma, LJ cutoff
1 0.1550 3.1536
2 0.0 0.0

But I get a message error : Expected integer parameter in input script or data file (…/read_data.cpp:2061)

It is because of the asterisk I guess but I don’t see why it generates an error or what syntax to use… I’ve tried to follow the doc for the coefficient arguments inthe pair_coeff command info

but you didn’t read the documentation that I pointed out to you. It clearly states that you have to provide exactly one line per atom type. there is no mention of wildcard parameters. the simple rule for reading the LAMMPS manual is: if it does not explicitly say you may do it, it is not likely supported. given the many features in LAMMPS it is impossible to list all permutations of things that don’t work. so we focus on describing what does work.

TL;DR if you want to use wildcard parameters you must use the pair_coeff command.

besides, your input is redundant. dropping the wildcard line will not make a difference, since the value of epsilon will be zero for the mixed interaction due to sqrt(eps1*eps2).

Axel.