Hi all, I would like to add new atom types in the charmm27.ff for futures simulations of glyolipids in water with gmx 4.5.1. I have finished to convert the bonded in GROMACS format. However, I am little puzzled with the vdW paramaters. I would like to know how to convert them (i.e. what are the conversion factors used to convert the CHARMM sigma and epsilon parameters to gromacs sigma and epsilon values ?). For example for the chloride atom CLA CHARMM 27 ; atom ignored epsilon Rmin/2 ignored eps,1-4 Rmin/2,1-4 CLA 0.0 -0.150 2.27 ! chloride GROMACS ffcharmmnb.itp ;name at.num mass charge ptype sigma epsilon CLA 17 35.450000 -1.00 A 0.404468018036 0.6276 Thanks in advance for your help Stefane -- 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
