Hi Ilya, Both rules 2 &3 are based in sigma/epsilon parameters. Cheers, Erik On Dec 15, 2003, at 8:40 PM, Ilya Chorny wrote: > > Hello If I switch my combination rules from 1 to 2. Will the values > listed > in the .itp files be read in as C12/C6 or sigma12/sigma6 values? > > Thanks > > Ilya > >