[gmx-users] rvdw>rlist for nve simulation

Linda fuwei at adrik.bchs.uh.edu
Tue May 4 05:58:01 CEST 2004


Hi, all, 

	I found gmx3.2.1 has fixed "rlist > rcoulomb" problem when executing grompp, while it still gives error message "With vdwtype = Cut-off,rvdw must be >= rlist" when setting "rlist > rvdw". I want to keep energy conserve when running NVE ensemble MD, so although someones have pointted out one must fix it by changging code, while I do not find how to fix it in mailing list archive. Can somebody help?? 

it is OK by just simply commenting out following code in src/kernel/readir.c?

  if ((ir->vdwtype == evdwSWITCH) || (ir->vdwtype == evdwSHIFT)) {
    sprintf(err_buf,"With vdwtype = %s rvdw_switch must be < rvdw",
            evdw_names[ir->vdwtype]);
    CHECK(ir->rvdw_switch >= ir->rvdw);
    if (ir->rvdw_switch > ir->rvdw-0.0999) {
      sprintf(warn_buf,"rvdw should be 0.1 to 0.3 nm larger than rvdw_switch to account for diffusion and the size of charge groups");
      warning(NULL);
    }
  } else {
    sprintf(err_buf,"With vdwtype = %s,rvdw must be >= rlist",evdw_names[ir->vdwtype]);
    CHECK(ir->rlist > ir->rvdw);
  }

 	Please correct me if I am wrong. Thx!

Linda





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