Fixed shift and switch modifiers, particularly for free-energy

[alexxy/gromacs.git] / src / mdlib / forcerec.c

diff --git a/src/mdlib/forcerec.c b/src/mdlib/forcerec.c
index 58fb1ea91350815e54d9263cdc7d432b05ef811c..78ccf4986ddfb7afe829bbdea84d6d3b81b402b1 100644 (file)
--- a/src/mdlib/forcerec.c
+++ b/src/mdlib/forcerec.c
@@ -2388,6 +2388,11 @@ void init_forcerec(FILE              *fp,
     fr->nbkernel_elec_modifier    = fr->coulomb_modifier;
     fr->nbkernel_vdw_modifier     = fr->vdw_modifier;
 
+    fr->rvdw             = cutoff_inf(ir->rvdw);
+    fr->rvdw_switch      = ir->rvdw_switch;
+    fr->rcoulomb         = cutoff_inf(ir->rcoulomb);
+    fr->rcoulomb_switch  = ir->rcoulomb_switch;
+
     fr->bTwinRange = fr->rlistlong > fr->rlist;
     fr->bEwald     = (EEL_PME(fr->eeltype) || fr->eeltype == eelEWALD);
 
@@ -2406,12 +2411,18 @@ void init_forcerec(FILE              *fp,
 
         /* If the user absolutely wants different switch/shift settings for coul/vdw, it is likely
          * going to be faster to tabulate the interaction than calling the generic kernel.
+         * However, if generic kernels have been requested we keep things analytically.
          */
-        if (fr->nbkernel_elec_modifier == eintmodPOTSWITCH && fr->nbkernel_vdw_modifier == eintmodPOTSWITCH)
+        if (fr->nbkernel_elec_modifier == eintmodPOTSWITCH &&
+            fr->nbkernel_vdw_modifier == eintmodPOTSWITCH &&
+            bGenericKernelOnly == FALSE)
         {
             if ((fr->rcoulomb_switch != fr->rvdw_switch) || (fr->rcoulomb != fr->rvdw))
             {
                 fr->bcoultab = TRUE;
+                /* Once we tabulate electrostatics, we can use the switch function for LJ,
+                 * which would otherwise need two tables.
+                 */
             }
         }
         else if ((fr->nbkernel_elec_modifier == eintmodPOTSHIFT && fr->nbkernel_vdw_modifier == eintmodPOTSHIFT) ||
@@ -2419,7 +2430,7 @@ void init_forcerec(FILE              *fp,
                    fr->nbkernel_elec_modifier == eintmodEXACTCUTOFF &&
                    (fr->nbkernel_vdw_modifier == eintmodPOTSWITCH || fr->nbkernel_vdw_modifier == eintmodPOTSHIFT))))
         {
-            if (fr->rcoulomb != fr->rvdw)
+            if ((fr->rcoulomb != fr->rvdw) && (bGenericKernelOnly == FALSE))
             {
                 fr->bcoultab = TRUE;
             }
@@ -2500,8 +2511,6 @@ void init_forcerec(FILE              *fp,
     fr->epsilon_r       = ir->epsilon_r;
     fr->epsilon_rf      = ir->epsilon_rf;
     fr->fudgeQQ         = mtop->ffparams.fudgeQQ;
-    fr->rcoulomb_switch = ir->rcoulomb_switch;
-    fr->rcoulomb        = cutoff_inf(ir->rcoulomb);
 
     /* Parameters for generalized RF */
     fr->zsquare = 0.0;
@@ -2557,8 +2566,6 @@ void init_forcerec(FILE              *fp,
     fr->egp_flags = ir->opts.egp_flags;
 
     /* Van der Waals stuff */
-    fr->rvdw        = cutoff_inf(ir->rvdw);
-    fr->rvdw_switch = ir->rvdw_switch;
     if ((fr->vdwtype != evdwCUT) && (fr->vdwtype != evdwUSER) && !fr->bBHAM)
     {
         if (fr->rvdw_switch >= fr->rvdw)
@@ -2691,6 +2698,8 @@ void init_forcerec(FILE              *fp,
     bTab = fr->bcoultab || fr->bvdwtab || fr->bEwald;
 
     bSep14tab = ((!bTab || fr->eeltype != eelCUT || fr->vdwtype != evdwCUT ||
+                  fr->coulomb_modifier != eintmodNONE ||
+                  fr->vdw_modifier != eintmodNONE ||
                   fr->bBHAM || fr->bEwald) &&
                  (gmx_mtop_ftype_count(mtop, F_LJ14) > 0 ||
                   gmx_mtop_ftype_count(mtop, F_LJC14_Q) > 0 ||
@@ -2809,6 +2818,15 @@ void init_forcerec(FILE              *fp,
             }
         }
     }
+    else if ((fr->eDispCorr != edispcNO) &&
+             ((fr->vdw_modifier == eintmodPOTSWITCH) || (fr->vdw_modifier == eintmodPOTSHIFT)))
+    {
+        /* Tables might not be used for the potential modifier interactions per se, but
+         * we still need them to evaluate switch/shift dispersion corrections in this case.
+         */
+        make_nbf_tables(fp, oenv, fr, rtab, cr, tabfn, NULL, NULL, &fr->nblists[0]);
+    }
+
     if (bSep14tab)
     {
         /* generate extra tables with plain Coulomb for 1-4 interactions only */