In general I would say that +2 is not a good choice, since it seems to me that this is a Zinc complex.
You may want to look at this: http://ambermd.org/tutorials/advanced/tutorial20/ZAFF.htm you should be able to create the topology in ambertools and then convert it to gromac with acpype (https://github.com/llazzaro/acpype) -----Original Message----- From: gromacs.org_gmx-users-boun...@maillist.sys.kth.se [mailto:gromacs.org_gmx-users-boun...@maillist.sys.kth.se] On Behalf Of milad bagheri Sent: 20. september 2018 14:28 To: gromacs.org_gmx-users@maillist.sys.kth.se Subject: [gmx-users] i have queston about partial charge zinc Hi I gonna MD simulation a protein that contained a zinc ion for build topology I used from the amber99sb force field Atomic charge is written "+2" in topology. I wanted to ask if this charge is correct or should be calculated in a different way? "PDB id 4row" sincerely -- Gromacs Users mailing list * Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/GMX-Users_List before posting! * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists * For (un)subscribe requests visit https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-users or send a mail to gmx-users-requ...@gromacs.org. -- Gromacs Users mailing list * Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/GMX-Users_List before posting! * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists * For (un)subscribe requests visit https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-users or send a mail to gmx-users-requ...@gromacs.org.