src/gromacs/gmxlib/nonbonded/nb_kernel_c/nb_kernel_ElecEwSw_VdwNone_GeomW3P1_c.c

   1 /*
   2  * This file is part of the GROMACS molecular simulation package.
   3  *
   4  * Copyright (c) 2012,2013,2014, by the GROMACS development team, led by
   5  * Mark Abraham, David van der Spoel, Berk Hess, and Erik Lindahl,
   6  * and including many others, as listed in the AUTHORS file in the
   7  * top-level source directory and at http://www.gromacs.org.
   8  *
   9  * GROMACS is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public License
  11  * as published by the Free Software Foundation; either version 2.1
  12  * of the License, or (at your option) any later version.
  13  *
  14  * GROMACS is distributed in the hope that it will be useful,
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  17  * Lesser General Public License for more details.
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  34  */
  35 /*
  36  * Note: this file was generated by the GROMACS c kernel generator.
  37  */
  38 #include "config.h"
  39
  40 #include <math.h>
  41
  42 #include "../nb_kernel.h"
  43 #include "gromacs/legacyheaders/types/simple.h"
  44 #include "gromacs/math/vec.h"
  45 #include "gromacs/legacyheaders/nrnb.h"
  46
  47 /*
  48  * Gromacs nonbonded kernel:   nb_kernel_ElecEwSw_VdwNone_GeomW3P1_VF_c
  49  * Electrostatics interaction: Ewald
  50  * VdW interaction:            None
  51  * Geometry:                   Water3-Particle
  52  * Calculate force/pot:        PotentialAndForce
  53  */
  54 void
  55 nb_kernel_ElecEwSw_VdwNone_GeomW3P1_VF_c
  56                     (t_nblist                    * gmx_restrict       nlist,
  57                      rvec                        * gmx_restrict          xx,
  58                      rvec                        * gmx_restrict          ff,
  59                      t_forcerec                  * gmx_restrict          fr,
  60                      t_mdatoms                   * gmx_restrict     mdatoms,
  61                      nb_kernel_data_t gmx_unused * gmx_restrict kernel_data,
  62                      t_nrnb                      * gmx_restrict        nrnb)
  63 {
  64     int              i_shift_offset,i_coord_offset,j_coord_offset;
  65     int              j_index_start,j_index_end;
  66     int              nri,inr,ggid,iidx,jidx,jnr,outeriter,inneriter;
  67     real             shX,shY,shZ,tx,ty,tz,fscal,rcutoff,rcutoff2;
  68     int              *iinr,*jindex,*jjnr,*shiftidx,*gid;
  69     real             *shiftvec,*fshift,*x,*f;
  70     int              vdwioffset0;
  71     real             ix0,iy0,iz0,fix0,fiy0,fiz0,iq0,isai0;
  72     int              vdwioffset1;
  73     real             ix1,iy1,iz1,fix1,fiy1,fiz1,iq1,isai1;
  74     int              vdwioffset2;
  75     real             ix2,iy2,iz2,fix2,fiy2,fiz2,iq2,isai2;
  76     int              vdwjidx0;
  77     real             jx0,jy0,jz0,fjx0,fjy0,fjz0,jq0,isaj0;
  78     real             dx00,dy00,dz00,rsq00,rinv00,rinvsq00,r00,qq00,c6_00,c12_00,cexp1_00,cexp2_00;
  79     real             dx10,dy10,dz10,rsq10,rinv10,rinvsq10,r10,qq10,c6_10,c12_10,cexp1_10,cexp2_10;
  80     real             dx20,dy20,dz20,rsq20,rinv20,rinvsq20,r20,qq20,c6_20,c12_20,cexp1_20,cexp2_20;
  81     real             velec,felec,velecsum,facel,crf,krf,krf2;
  82     real             *charge;
  83     int              ewitab;
  84     real             ewtabscale,eweps,sh_ewald,ewrt,ewtabhalfspace;
  85     real             *ewtab;
  86     real             rswitch,swV3,swV4,swV5,swF2,swF3,swF4,d,d2,sw,dsw;
  87
  88     x                = xx[0];
  89     f                = ff[0];
  90
  91     nri              = nlist->nri;
  92     iinr             = nlist->iinr;
  93     jindex           = nlist->jindex;
  94     jjnr             = nlist->jjnr;
  95     shiftidx         = nlist->shift;
  96     gid              = nlist->gid;
  97     shiftvec         = fr->shift_vec[0];
  98     fshift           = fr->fshift[0];
  99     facel            = fr->epsfac;
 100     charge           = mdatoms->chargeA;
 101
 102     sh_ewald         = fr->ic->sh_ewald;
 103     ewtab            = fr->ic->tabq_coul_FDV0;
 104     ewtabscale       = fr->ic->tabq_scale;
 105     ewtabhalfspace   = 0.5/ewtabscale;
 106
 107     /* Setup water-specific parameters */
 108     inr              = nlist->iinr[0];
 109     iq0              = facel*charge[inr+0];
 110     iq1              = facel*charge[inr+1];
 111     iq2              = facel*charge[inr+2];
 112
 113     /* When we use explicit cutoffs the value must be identical for elec and VdW, so use elec as an arbitrary choice */
 114     rcutoff          = fr->rcoulomb;
 115     rcutoff2         = rcutoff*rcutoff;
 116
 117     rswitch          = fr->rcoulomb_switch;
 118     /* Setup switch parameters */
 119     d                = rcutoff-rswitch;
 120     swV3             = -10.0/(d*d*d);
 121     swV4             =  15.0/(d*d*d*d);
 122     swV5             =  -6.0/(d*d*d*d*d);
 123     swF2             = -30.0/(d*d*d);
 124     swF3             =  60.0/(d*d*d*d);
 125     swF4             = -30.0/(d*d*d*d*d);
 126
 127     outeriter        = 0;
 128     inneriter        = 0;
 129
 130     /* Start outer loop over neighborlists */
 131     for(iidx=0; iidx<nri; iidx++)
 132     {
 133         /* Load shift vector for this list */
 134         i_shift_offset   = DIM*shiftidx[iidx];
 135         shX              = shiftvec[i_shift_offset+XX];
 136         shY              = shiftvec[i_shift_offset+YY];
 137         shZ              = shiftvec[i_shift_offset+ZZ];
 138
 139         /* Load limits for loop over neighbors */
 140         j_index_start    = jindex[iidx];
 141         j_index_end      = jindex[iidx+1];
 142
 143         /* Get outer coordinate index */
 144         inr              = iinr[iidx];
 145         i_coord_offset   = DIM*inr;
 146
 147         /* Load i particle coords and add shift vector */
 148         ix0              = shX + x[i_coord_offset+DIM*0+XX];
 149         iy0              = shY + x[i_coord_offset+DIM*0+YY];
 150         iz0              = shZ + x[i_coord_offset+DIM*0+ZZ];
 151         ix1              = shX + x[i_coord_offset+DIM*1+XX];
 152         iy1              = shY + x[i_coord_offset+DIM*1+YY];
 153         iz1              = shZ + x[i_coord_offset+DIM*1+ZZ];
 154         ix2              = shX + x[i_coord_offset+DIM*2+XX];
 155         iy2              = shY + x[i_coord_offset+DIM*2+YY];
 156         iz2              = shZ + x[i_coord_offset+DIM*2+ZZ];
 157
 158         fix0             = 0.0;
 159         fiy0             = 0.0;
 160         fiz0             = 0.0;
 161         fix1             = 0.0;
 162         fiy1             = 0.0;
 163         fiz1             = 0.0;
 164         fix2             = 0.0;
 165         fiy2             = 0.0;
 166         fiz2             = 0.0;
 167
 168         /* Reset potential sums */
 169         velecsum         = 0.0;
 170
 171         /* Start inner kernel loop */
 172         for(jidx=j_index_start; jidx<j_index_end; jidx++)
 173         {
 174             /* Get j neighbor index, and coordinate index */
 175             jnr              = jjnr[jidx];
 176             j_coord_offset   = DIM*jnr;
 177
 178             /* load j atom coordinates */
 179             jx0              = x[j_coord_offset+DIM*0+XX];
 180             jy0              = x[j_coord_offset+DIM*0+YY];
 181             jz0              = x[j_coord_offset+DIM*0+ZZ];
 182
 183             /* Calculate displacement vector */
 184             dx00             = ix0 - jx0;
 185             dy00             = iy0 - jy0;
 186             dz00             = iz0 - jz0;
 187             dx10             = ix1 - jx0;
 188             dy10             = iy1 - jy0;
 189             dz10             = iz1 - jz0;
 190             dx20             = ix2 - jx0;
 191             dy20             = iy2 - jy0;
 192             dz20             = iz2 - jz0;
 193
 194             /* Calculate squared distance and things based on it */
 195             rsq00            = dx00*dx00+dy00*dy00+dz00*dz00;
 196             rsq10            = dx10*dx10+dy10*dy10+dz10*dz10;
 197             rsq20            = dx20*dx20+dy20*dy20+dz20*dz20;
 198
 199             rinv00           = gmx_invsqrt(rsq00);
 200             rinv10           = gmx_invsqrt(rsq10);
 201             rinv20           = gmx_invsqrt(rsq20);
 202
 203             rinvsq00         = rinv00*rinv00;
 204             rinvsq10         = rinv10*rinv10;
 205             rinvsq20         = rinv20*rinv20;
 206
 207             /* Load parameters for j particles */
 208             jq0              = charge[jnr+0];
 209
 210             /**************************
 211              * CALCULATE INTERACTIONS *
 212              **************************/
 213
 214             if (rsq00<rcutoff2)
 215             {
 216
 217             r00              = rsq00*rinv00;
 218
 219             qq00             = iq0*jq0;
 220
 221             /* EWALD ELECTROSTATICS */
 222
 223             /* Calculate Ewald table index by multiplying r with scale and truncate to integer */
 224             ewrt             = r00*ewtabscale;
 225             ewitab           = ewrt;
 226             eweps            = ewrt-ewitab;
 227             ewitab           = 4*ewitab;
 228             felec            = ewtab[ewitab]+eweps*ewtab[ewitab+1];
 229             velec            = qq00*(rinv00-(ewtab[ewitab+2]-ewtabhalfspace*eweps*(ewtab[ewitab]+felec)));
 230             felec            = qq00*rinv00*(rinvsq00-felec);
 231
 232             d                = r00-rswitch;
 233             d                = (d>0.0) ? d : 0.0;
 234             d2               = d*d;
 235             sw               = 1.0+d2*d*(swV3+d*(swV4+d*swV5));
 236
 237             dsw              = d2*(swF2+d*(swF3+d*swF4));
 238
 239             /* Evaluate switch function */
 240             /* fscal'=f'/r=-(v*sw)'/r=-(v'*sw+v*dsw)/r=-v'*sw/r-v*dsw/r=fscal*sw-v*dsw/r */
 241             felec            = felec*sw - rinv00*velec*dsw;
 242             velec           *= sw;
 243
 244             /* Update potential sums from outer loop */
 245             velecsum        += velec;
 246
 247             fscal            = felec;
 248
 249             /* Calculate temporary vectorial force */
 250             tx               = fscal*dx00;
 251             ty               = fscal*dy00;
 252             tz               = fscal*dz00;
 253
 254             /* Update vectorial force */
 255             fix0            += tx;
 256             fiy0            += ty;
 257             fiz0            += tz;
 258             f[j_coord_offset+DIM*0+XX] -= tx;
 259             f[j_coord_offset+DIM*0+YY] -= ty;
 260             f[j_coord_offset+DIM*0+ZZ] -= tz;
 261
 262             }
 263
 264             /**************************
 265              * CALCULATE INTERACTIONS *
 266              **************************/
 267
 268             if (rsq10<rcutoff2)
 269             {
 270
 271             r10              = rsq10*rinv10;
 272
 273             qq10             = iq1*jq0;
 274
 275             /* EWALD ELECTROSTATICS */
 276
 277             /* Calculate Ewald table index by multiplying r with scale and truncate to integer */
 278             ewrt             = r10*ewtabscale;
 279             ewitab           = ewrt;
 280             eweps            = ewrt-ewitab;
 281             ewitab           = 4*ewitab;
 282             felec            = ewtab[ewitab]+eweps*ewtab[ewitab+1];
 283             velec            = qq10*(rinv10-(ewtab[ewitab+2]-ewtabhalfspace*eweps*(ewtab[ewitab]+felec)));
 284             felec            = qq10*rinv10*(rinvsq10-felec);
 285
 286             d                = r10-rswitch;
 287             d                = (d>0.0) ? d : 0.0;
 288             d2               = d*d;
 289             sw               = 1.0+d2*d*(swV3+d*(swV4+d*swV5));
 290
 291             dsw              = d2*(swF2+d*(swF3+d*swF4));
 292
 293             /* Evaluate switch function */
 294             /* fscal'=f'/r=-(v*sw)'/r=-(v'*sw+v*dsw)/r=-v'*sw/r-v*dsw/r=fscal*sw-v*dsw/r */
 295             felec            = felec*sw - rinv10*velec*dsw;
 296             velec           *= sw;
 297
 298             /* Update potential sums from outer loop */
 299             velecsum        += velec;
 300
 301             fscal            = felec;
 302
 303             /* Calculate temporary vectorial force */
 304             tx               = fscal*dx10;
 305             ty               = fscal*dy10;
 306             tz               = fscal*dz10;
 307
 308             /* Update vectorial force */
 309             fix1            += tx;
 310             fiy1            += ty;
 311             fiz1            += tz;
 312             f[j_coord_offset+DIM*0+XX] -= tx;
 313             f[j_coord_offset+DIM*0+YY] -= ty;
 314             f[j_coord_offset+DIM*0+ZZ] -= tz;
 315
 316             }
 317
 318             /**************************
 319              * CALCULATE INTERACTIONS *
 320              **************************/
 321
 322             if (rsq20<rcutoff2)
 323             {
 324
 325             r20              = rsq20*rinv20;
 326
 327             qq20             = iq2*jq0;
 328
 329             /* EWALD ELECTROSTATICS */
 330
 331             /* Calculate Ewald table index by multiplying r with scale and truncate to integer */
 332             ewrt             = r20*ewtabscale;
 333             ewitab           = ewrt;
 334             eweps            = ewrt-ewitab;
 335             ewitab           = 4*ewitab;
 336             felec            = ewtab[ewitab]+eweps*ewtab[ewitab+1];
 337             velec            = qq20*(rinv20-(ewtab[ewitab+2]-ewtabhalfspace*eweps*(ewtab[ewitab]+felec)));
 338             felec            = qq20*rinv20*(rinvsq20-felec);
 339
 340             d                = r20-rswitch;
 341             d                = (d>0.0) ? d : 0.0;
 342             d2               = d*d;
 343             sw               = 1.0+d2*d*(swV3+d*(swV4+d*swV5));
 344
 345             dsw              = d2*(swF2+d*(swF3+d*swF4));
 346
 347             /* Evaluate switch function */
 348             /* fscal'=f'/r=-(v*sw)'/r=-(v'*sw+v*dsw)/r=-v'*sw/r-v*dsw/r=fscal*sw-v*dsw/r */
 349             felec            = felec*sw - rinv20*velec*dsw;
 350             velec           *= sw;
 351
 352             /* Update potential sums from outer loop */
 353             velecsum        += velec;
 354
 355             fscal            = felec;
 356
 357             /* Calculate temporary vectorial force */
 358             tx               = fscal*dx20;
 359             ty               = fscal*dy20;
 360             tz               = fscal*dz20;
 361
 362             /* Update vectorial force */
 363             fix2            += tx;
 364             fiy2            += ty;
 365             fiz2            += tz;
 366             f[j_coord_offset+DIM*0+XX] -= tx;
 367             f[j_coord_offset+DIM*0+YY] -= ty;
 368             f[j_coord_offset+DIM*0+ZZ] -= tz;
 369
 370             }
 371
 372             /* Inner loop uses 177 flops */
 373         }
 374         /* End of innermost loop */
 375
 376         tx = ty = tz = 0;
 377         f[i_coord_offset+DIM*0+XX] += fix0;
 378         f[i_coord_offset+DIM*0+YY] += fiy0;
 379         f[i_coord_offset+DIM*0+ZZ] += fiz0;
 380         tx                         += fix0;
 381         ty                         += fiy0;
 382         tz                         += fiz0;
 383         f[i_coord_offset+DIM*1+XX] += fix1;
 384         f[i_coord_offset+DIM*1+YY] += fiy1;
 385         f[i_coord_offset+DIM*1+ZZ] += fiz1;
 386         tx                         += fix1;
 387         ty                         += fiy1;
 388         tz                         += fiz1;
 389         f[i_coord_offset+DIM*2+XX] += fix2;
 390         f[i_coord_offset+DIM*2+YY] += fiy2;
 391         f[i_coord_offset+DIM*2+ZZ] += fiz2;
 392         tx                         += fix2;
 393         ty                         += fiy2;
 394         tz                         += fiz2;
 395         fshift[i_shift_offset+XX]  += tx;
 396         fshift[i_shift_offset+YY]  += ty;
 397         fshift[i_shift_offset+ZZ]  += tz;
 398
 399         ggid                        = gid[iidx];
 400         /* Update potential energies */
 401         kernel_data->energygrp_elec[ggid] += velecsum;
 402
 403         /* Increment number of inner iterations */
 404         inneriter                  += j_index_end - j_index_start;
 405
 406         /* Outer loop uses 31 flops */
 407     }
 408
 409     /* Increment number of outer iterations */
 410     outeriter        += nri;
 411
 412     /* Update outer/inner flops */
 413
 414     inc_nrnb(nrnb,eNR_NBKERNEL_ELEC_W3_VF,outeriter*31 + inneriter*177);
 415 }
 416 /*
 417  * Gromacs nonbonded kernel:   nb_kernel_ElecEwSw_VdwNone_GeomW3P1_F_c
 418  * Electrostatics interaction: Ewald
 419  * VdW interaction:            None
 420  * Geometry:                   Water3-Particle
 421  * Calculate force/pot:        Force
 422  */
 423 void
 424 nb_kernel_ElecEwSw_VdwNone_GeomW3P1_F_c
 425                     (t_nblist                    * gmx_restrict       nlist,
 426                      rvec                        * gmx_restrict          xx,
 427                      rvec                        * gmx_restrict          ff,
 428                      t_forcerec                  * gmx_restrict          fr,
 429                      t_mdatoms                   * gmx_restrict     mdatoms,
 430                      nb_kernel_data_t gmx_unused * gmx_restrict kernel_data,
 431                      t_nrnb                      * gmx_restrict        nrnb)
 432 {
 433     int              i_shift_offset,i_coord_offset,j_coord_offset;
 434     int              j_index_start,j_index_end;
 435     int              nri,inr,ggid,iidx,jidx,jnr,outeriter,inneriter;
 436     real             shX,shY,shZ,tx,ty,tz,fscal,rcutoff,rcutoff2;
 437     int              *iinr,*jindex,*jjnr,*shiftidx,*gid;
 438     real             *shiftvec,*fshift,*x,*f;
 439     int              vdwioffset0;
 440     real             ix0,iy0,iz0,fix0,fiy0,fiz0,iq0,isai0;
 441     int              vdwioffset1;
 442     real             ix1,iy1,iz1,fix1,fiy1,fiz1,iq1,isai1;
 443     int              vdwioffset2;
 444     real             ix2,iy2,iz2,fix2,fiy2,fiz2,iq2,isai2;
 445     int              vdwjidx0;
 446     real             jx0,jy0,jz0,fjx0,fjy0,fjz0,jq0,isaj0;
 447     real             dx00,dy00,dz00,rsq00,rinv00,rinvsq00,r00,qq00,c6_00,c12_00,cexp1_00,cexp2_00;
 448     real             dx10,dy10,dz10,rsq10,rinv10,rinvsq10,r10,qq10,c6_10,c12_10,cexp1_10,cexp2_10;
 449     real             dx20,dy20,dz20,rsq20,rinv20,rinvsq20,r20,qq20,c6_20,c12_20,cexp1_20,cexp2_20;
 450     real             velec,felec,velecsum,facel,crf,krf,krf2;
 451     real             *charge;
 452     int              ewitab;
 453     real             ewtabscale,eweps,sh_ewald,ewrt,ewtabhalfspace;
 454     real             *ewtab;
 455     real             rswitch,swV3,swV4,swV5,swF2,swF3,swF4,d,d2,sw,dsw;
 456
 457     x                = xx[0];
 458     f                = ff[0];
 459
 460     nri              = nlist->nri;
 461     iinr             = nlist->iinr;
 462     jindex           = nlist->jindex;
 463     jjnr             = nlist->jjnr;
 464     shiftidx         = nlist->shift;
 465     gid              = nlist->gid;
 466     shiftvec         = fr->shift_vec[0];
 467     fshift           = fr->fshift[0];
 468     facel            = fr->epsfac;
 469     charge           = mdatoms->chargeA;
 470
 471     sh_ewald         = fr->ic->sh_ewald;
 472     ewtab            = fr->ic->tabq_coul_FDV0;
 473     ewtabscale       = fr->ic->tabq_scale;
 474     ewtabhalfspace   = 0.5/ewtabscale;
 475
 476     /* Setup water-specific parameters */
 477     inr              = nlist->iinr[0];
 478     iq0              = facel*charge[inr+0];
 479     iq1              = facel*charge[inr+1];
 480     iq2              = facel*charge[inr+2];
 481
 482     /* When we use explicit cutoffs the value must be identical for elec and VdW, so use elec as an arbitrary choice */
 483     rcutoff          = fr->rcoulomb;
 484     rcutoff2         = rcutoff*rcutoff;
 485
 486     rswitch          = fr->rcoulomb_switch;
 487     /* Setup switch parameters */
 488     d                = rcutoff-rswitch;
 489     swV3             = -10.0/(d*d*d);
 490     swV4             =  15.0/(d*d*d*d);
 491     swV5             =  -6.0/(d*d*d*d*d);
 492     swF2             = -30.0/(d*d*d);
 493     swF3             =  60.0/(d*d*d*d);
 494     swF4             = -30.0/(d*d*d*d*d);
 495
 496     outeriter        = 0;
 497     inneriter        = 0;
 498
 499     /* Start outer loop over neighborlists */
 500     for(iidx=0; iidx<nri; iidx++)
 501     {
 502         /* Load shift vector for this list */
 503         i_shift_offset   = DIM*shiftidx[iidx];
 504         shX              = shiftvec[i_shift_offset+XX];
 505         shY              = shiftvec[i_shift_offset+YY];
 506         shZ              = shiftvec[i_shift_offset+ZZ];
 507
 508         /* Load limits for loop over neighbors */
 509         j_index_start    = jindex[iidx];
 510         j_index_end      = jindex[iidx+1];
 511
 512         /* Get outer coordinate index */
 513         inr              = iinr[iidx];
 514         i_coord_offset   = DIM*inr;
 515
 516         /* Load i particle coords and add shift vector */
 517         ix0              = shX + x[i_coord_offset+DIM*0+XX];
 518         iy0              = shY + x[i_coord_offset+DIM*0+YY];
 519         iz0              = shZ + x[i_coord_offset+DIM*0+ZZ];
 520         ix1              = shX + x[i_coord_offset+DIM*1+XX];
 521         iy1              = shY + x[i_coord_offset+DIM*1+YY];
 522         iz1              = shZ + x[i_coord_offset+DIM*1+ZZ];
 523         ix2              = shX + x[i_coord_offset+DIM*2+XX];
 524         iy2              = shY + x[i_coord_offset+DIM*2+YY];
 525         iz2              = shZ + x[i_coord_offset+DIM*2+ZZ];
 526
 527         fix0             = 0.0;
 528         fiy0             = 0.0;
 529         fiz0             = 0.0;
 530         fix1             = 0.0;
 531         fiy1             = 0.0;
 532         fiz1             = 0.0;
 533         fix2             = 0.0;
 534         fiy2             = 0.0;
 535         fiz2             = 0.0;
 536
 537         /* Start inner kernel loop */
 538         for(jidx=j_index_start; jidx<j_index_end; jidx++)
 539         {
 540             /* Get j neighbor index, and coordinate index */
 541             jnr              = jjnr[jidx];
 542             j_coord_offset   = DIM*jnr;
 543
 544             /* load j atom coordinates */
 545             jx0              = x[j_coord_offset+DIM*0+XX];
 546             jy0              = x[j_coord_offset+DIM*0+YY];
 547             jz0              = x[j_coord_offset+DIM*0+ZZ];
 548
 549             /* Calculate displacement vector */
 550             dx00             = ix0 - jx0;
 551             dy00             = iy0 - jy0;
 552             dz00             = iz0 - jz0;
 553             dx10             = ix1 - jx0;
 554             dy10             = iy1 - jy0;
 555             dz10             = iz1 - jz0;
 556             dx20             = ix2 - jx0;
 557             dy20             = iy2 - jy0;
 558             dz20             = iz2 - jz0;
 559
 560             /* Calculate squared distance and things based on it */
 561             rsq00            = dx00*dx00+dy00*dy00+dz00*dz00;
 562             rsq10            = dx10*dx10+dy10*dy10+dz10*dz10;
 563             rsq20            = dx20*dx20+dy20*dy20+dz20*dz20;
 564
 565             rinv00           = gmx_invsqrt(rsq00);
 566             rinv10           = gmx_invsqrt(rsq10);
 567             rinv20           = gmx_invsqrt(rsq20);
 568
 569             rinvsq00         = rinv00*rinv00;
 570             rinvsq10         = rinv10*rinv10;
 571             rinvsq20         = rinv20*rinv20;
 572
 573             /* Load parameters for j particles */
 574             jq0              = charge[jnr+0];
 575
 576             /**************************
 577              * CALCULATE INTERACTIONS *
 578              **************************/
 579
 580             if (rsq00<rcutoff2)
 581             {
 582
 583             r00              = rsq00*rinv00;
 584
 585             qq00             = iq0*jq0;
 586
 587             /* EWALD ELECTROSTATICS */
 588
 589             /* Calculate Ewald table index by multiplying r with scale and truncate to integer */
 590             ewrt             = r00*ewtabscale;
 591             ewitab           = ewrt;
 592             eweps            = ewrt-ewitab;
 593             ewitab           = 4*ewitab;
 594             felec            = ewtab[ewitab]+eweps*ewtab[ewitab+1];
 595             velec            = qq00*(rinv00-(ewtab[ewitab+2]-ewtabhalfspace*eweps*(ewtab[ewitab]+felec)));
 596             felec            = qq00*rinv00*(rinvsq00-felec);
 597
 598             d                = r00-rswitch;
 599             d                = (d>0.0) ? d : 0.0;
 600             d2               = d*d;
 601             sw               = 1.0+d2*d*(swV3+d*(swV4+d*swV5));
 602
 603             dsw              = d2*(swF2+d*(swF3+d*swF4));
 604
 605             /* Evaluate switch function */
 606             /* fscal'=f'/r=-(v*sw)'/r=-(v'*sw+v*dsw)/r=-v'*sw/r-v*dsw/r=fscal*sw-v*dsw/r */
 607             felec            = felec*sw - rinv00*velec*dsw;
 608
 609             fscal            = felec;
 610
 611             /* Calculate temporary vectorial force */
 612             tx               = fscal*dx00;
 613             ty               = fscal*dy00;
 614             tz               = fscal*dz00;
 615
 616             /* Update vectorial force */
 617             fix0            += tx;
 618             fiy0            += ty;
 619             fiz0            += tz;
 620             f[j_coord_offset+DIM*0+XX] -= tx;
 621             f[j_coord_offset+DIM*0+YY] -= ty;
 622             f[j_coord_offset+DIM*0+ZZ] -= tz;
 623
 624             }
 625
 626             /**************************
 627              * CALCULATE INTERACTIONS *
 628              **************************/
 629
 630             if (rsq10<rcutoff2)
 631             {
 632
 633             r10              = rsq10*rinv10;
 634
 635             qq10             = iq1*jq0;
 636
 637             /* EWALD ELECTROSTATICS */
 638
 639             /* Calculate Ewald table index by multiplying r with scale and truncate to integer */
 640             ewrt             = r10*ewtabscale;
 641             ewitab           = ewrt;
 642             eweps            = ewrt-ewitab;
 643             ewitab           = 4*ewitab;
 644             felec            = ewtab[ewitab]+eweps*ewtab[ewitab+1];
 645             velec            = qq10*(rinv10-(ewtab[ewitab+2]-ewtabhalfspace*eweps*(ewtab[ewitab]+felec)));
 646             felec            = qq10*rinv10*(rinvsq10-felec);
 647
 648             d                = r10-rswitch;
 649             d                = (d>0.0) ? d : 0.0;
 650             d2               = d*d;
 651             sw               = 1.0+d2*d*(swV3+d*(swV4+d*swV5));
 652
 653             dsw              = d2*(swF2+d*(swF3+d*swF4));
 654
 655             /* Evaluate switch function */
 656             /* fscal'=f'/r=-(v*sw)'/r=-(v'*sw+v*dsw)/r=-v'*sw/r-v*dsw/r=fscal*sw-v*dsw/r */
 657             felec            = felec*sw - rinv10*velec*dsw;
 658
 659             fscal            = felec;
 660
 661             /* Calculate temporary vectorial force */
 662             tx               = fscal*dx10;
 663             ty               = fscal*dy10;
 664             tz               = fscal*dz10;
 665
 666             /* Update vectorial force */
 667             fix1            += tx;
 668             fiy1            += ty;
 669             fiz1            += tz;
 670             f[j_coord_offset+DIM*0+XX] -= tx;
 671             f[j_coord_offset+DIM*0+YY] -= ty;
 672             f[j_coord_offset+DIM*0+ZZ] -= tz;
 673
 674             }
 675
 676             /**************************
 677              * CALCULATE INTERACTIONS *
 678              **************************/
 679
 680             if (rsq20<rcutoff2)
 681             {
 682
 683             r20              = rsq20*rinv20;
 684
 685             qq20             = iq2*jq0;
 686
 687             /* EWALD ELECTROSTATICS */
 688
 689             /* Calculate Ewald table index by multiplying r with scale and truncate to integer */
 690             ewrt             = r20*ewtabscale;
 691             ewitab           = ewrt;
 692             eweps            = ewrt-ewitab;
 693             ewitab           = 4*ewitab;
 694             felec            = ewtab[ewitab]+eweps*ewtab[ewitab+1];
 695             velec            = qq20*(rinv20-(ewtab[ewitab+2]-ewtabhalfspace*eweps*(ewtab[ewitab]+felec)));
 696             felec            = qq20*rinv20*(rinvsq20-felec);
 697
 698             d                = r20-rswitch;
 699             d                = (d>0.0) ? d : 0.0;
 700             d2               = d*d;
 701             sw               = 1.0+d2*d*(swV3+d*(swV4+d*swV5));
 702
 703             dsw              = d2*(swF2+d*(swF3+d*swF4));
 704
 705             /* Evaluate switch function */
 706             /* fscal'=f'/r=-(v*sw)'/r=-(v'*sw+v*dsw)/r=-v'*sw/r-v*dsw/r=fscal*sw-v*dsw/r */
 707             felec            = felec*sw - rinv20*velec*dsw;
 708
 709             fscal            = felec;
 710
 711             /* Calculate temporary vectorial force */
 712             tx               = fscal*dx20;
 713             ty               = fscal*dy20;
 714             tz               = fscal*dz20;
 715
 716             /* Update vectorial force */
 717             fix2            += tx;
 718             fiy2            += ty;
 719             fiz2            += tz;
 720             f[j_coord_offset+DIM*0+XX] -= tx;
 721             f[j_coord_offset+DIM*0+YY] -= ty;
 722             f[j_coord_offset+DIM*0+ZZ] -= tz;
 723
 724             }
 725
 726             /* Inner loop uses 171 flops */
 727         }
 728         /* End of innermost loop */
 729
 730         tx = ty = tz = 0;
 731         f[i_coord_offset+DIM*0+XX] += fix0;
 732         f[i_coord_offset+DIM*0+YY] += fiy0;
 733         f[i_coord_offset+DIM*0+ZZ] += fiz0;
 734         tx                         += fix0;
 735         ty                         += fiy0;
 736         tz                         += fiz0;
 737         f[i_coord_offset+DIM*1+XX] += fix1;
 738         f[i_coord_offset+DIM*1+YY] += fiy1;
 739         f[i_coord_offset+DIM*1+ZZ] += fiz1;
 740         tx                         += fix1;
 741         ty                         += fiy1;
 742         tz                         += fiz1;
 743         f[i_coord_offset+DIM*2+XX] += fix2;
 744         f[i_coord_offset+DIM*2+YY] += fiy2;
 745         f[i_coord_offset+DIM*2+ZZ] += fiz2;
 746         tx                         += fix2;
 747         ty                         += fiy2;
 748         tz                         += fiz2;
 749         fshift[i_shift_offset+XX]  += tx;
 750         fshift[i_shift_offset+YY]  += ty;
 751         fshift[i_shift_offset+ZZ]  += tz;
 752
 753         /* Increment number of inner iterations */
 754         inneriter                  += j_index_end - j_index_start;
 755
 756         /* Outer loop uses 30 flops */
 757     }
 758
 759     /* Increment number of outer iterations */
 760     outeriter        += nri;
 761
 762     /* Update outer/inner flops */
 763
 764     inc_nrnb(nrnb,eNR_NBKERNEL_ELEC_W3_F,outeriter*30 + inneriter*171);
 765 }