I'm little confused with using "pair_coeff" command. I'd read doc's
about it but not clearly understand what this coefficients mean. So,
for exapmle, what coefficients should I use for describing
interactions of gas and metal moleculas. Can you write some words
this cannot be answered in a simple e-mail. therefore
please have a look into a text book on molecular dynamics,
e.g. frenkel/smit, understanding molecular simulations.
please note, that the documentation coming with MD codes
usually assumes that you know what you are doing, and only
explains the technical details.