[gmx-users] About Tabulated Potentials

[zhangzhengc]

Dear all,
         I want to add the Morse potential for nonbonded interactions between CH4 and CH4. I used three table files each contain seven columns to add the H to H, H to C, and C to C Morse form interactions. I set Coulombtype=user, vdwtype=user , and Dispcorr = no, and add energrps and energrps_table in the mdp file. However, when I did NVT simulations, I didnot get accurate pressure for my pure methane system. Actually the pressure is 20 Mpa smaller. Could you tell what is wrong with my set or what I missed in adding tabulated potentials? I tested the using of tabulated potentials with LJ form potential, It works very well.
      Look forward to your reply,
     Sincerely yours
     Zhengcai,