Thanks for your reply. Sorry for my careless, and the input script have attached. I have investigated GCMC three years, and got good results using pressure and fugacity_coeff, which calculated from PR-EOS. But, some reviewers would query the application of EOS and suggest to get chemical potential from Widom or FEP. In fact, I have been studying the Widom or FEP for a long time. Widom insertion method have been realized in lammps, but I found it is invalid under high pressure. So, I turned to FEP method. I have read many text books like Understanding molecular dynamics carefully, but I can not get substantial help from them. This is the second time I have asked this question in lammps mail-list, I really hope you can give me some suggestions that can help me truly, even some useful papers or text books. Thank you very much!
in.fep (2.45 KB)