Hi All I have set up a topology file and with virtual sites (exerpts below), whereby my virtual sites only interact with the C3 atoms. I am trying to construct a PMF wrt one particular C3. This atom I do not want to interact with the virtual sites at all. I thought the best way to do this was via energy exclusion groups. So I set up some groups in the index file (see below), and defined the energy groups like so energygrps = vsites vsitex energygrp_excl = vsites vsitex
but I get the following error Fatal error: atoms 415 and 416 in charge group 89 of molecule type 'name' are in different energy groups I have no charge group 89 in my molecule. Can someone please suggest where I might be going wrong. ;Parameter level [defaults] ; nbfunc comb-rule gen-pairs fudgeLJ fudgeQQ 1 3 yes 0.5 0.5 [atomtypes] ;type mass charge ptype sigma(nm) epsilon(kjmol-1) CB 12.011000 0.000000 A 0.355000 0.292880 CA 12.011000 -0.115000 A 0.355000 0.292880 HC 1.008000 0.115000 A 0.242000 0.125520 CU 13.019000 0.265000 A 0.350000 0.334720 NU 14.007000 -0.597000 A 0.325000 0.711280 CH 13.019000 0.332000 A 0.385000 0.334720 C3 15.035000 0.000000 A 0.391000 0.669440 C2 14.027000 0.000000 A 0.390500 0.493712 VS 0.0 0.0 V 0.0 0.0 [nonbond_params] ;i j funct sigma epsilon VS C3 1 0.1 0.03153 [ cage_1 ] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 75 89 103 117 131 145 159 173 187 201 215 [ tail ] 416 [ vsites ] 229 230 231 232 461 462 463 464 [ vsitex ] 416 -- gmx-users mailing list gmx-users@gromacs.org http://lists.gromacs.org/mailman/listinfo/gmx-users Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/Search before posting! Please don't post (un)subscribe requests to the list. Use the www interface or send it to gmx-users-requ...@gromacs.org. Can't post? Read http://www.gromacs.org/Support/Mailing_Lists