src/gromacs/gmxlib/nonbonded/nb_kernel_c/nb_kernel_ElecEwSh_VdwBhamSh_GeomW4P1_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 "types/simple.h"
  44 #include "gromacs/math/vec.h"
  45 #include "nrnb.h"
  46
  47 /*
  48  * Gromacs nonbonded kernel:   nb_kernel_ElecEwSh_VdwBhamSh_GeomW4P1_VF_c
  49  * Electrostatics interaction: Ewald
  50  * VdW interaction:            Buckingham
  51  * Geometry:                   Water4-Particle
  52  * Calculate force/pot:        PotentialAndForce
  53  */
  54 void
  55 nb_kernel_ElecEwSh_VdwBhamSh_GeomW4P1_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              vdwioffset3;
  77     real             ix3,iy3,iz3,fix3,fiy3,fiz3,iq3,isai3;
  78     int              vdwjidx0;
  79     real             jx0,jy0,jz0,fjx0,fjy0,fjz0,jq0,isaj0;
  80     real             dx00,dy00,dz00,rsq00,rinv00,rinvsq00,r00,qq00,c6_00,c12_00,cexp1_00,cexp2_00;
  81     real             dx10,dy10,dz10,rsq10,rinv10,rinvsq10,r10,qq10,c6_10,c12_10,cexp1_10,cexp2_10;
  82     real             dx20,dy20,dz20,rsq20,rinv20,rinvsq20,r20,qq20,c6_20,c12_20,cexp1_20,cexp2_20;
  83     real             dx30,dy30,dz30,rsq30,rinv30,rinvsq30,r30,qq30,c6_30,c12_30,cexp1_30,cexp2_30;
  84     real             velec,felec,velecsum,facel,crf,krf,krf2;
  85     real             *charge;
  86     int              nvdwtype;
  87     real             rinvsix,rvdw,vvdw,vvdw6,vvdw12,fvdw,fvdw6,fvdw12,vvdwsum,br,vvdwexp,sh_vdw_invrcut6;
  88     int              *vdwtype;
  89     real             *vdwparam;
  90     int              ewitab;
  91     real             ewtabscale,eweps,sh_ewald,ewrt,ewtabhalfspace;
  92     real             *ewtab;
  93
  94     x                = xx[0];
  95     f                = ff[0];
  96
  97     nri              = nlist->nri;
  98     iinr             = nlist->iinr;
  99     jindex           = nlist->jindex;
 100     jjnr             = nlist->jjnr;
 101     shiftidx         = nlist->shift;
 102     gid              = nlist->gid;
 103     shiftvec         = fr->shift_vec[0];
 104     fshift           = fr->fshift[0];
 105     facel            = fr->epsfac;
 106     charge           = mdatoms->chargeA;
 107     nvdwtype         = fr->ntype;
 108     vdwparam         = fr->nbfp;
 109     vdwtype          = mdatoms->typeA;
 110
 111     sh_ewald         = fr->ic->sh_ewald;
 112     ewtab            = fr->ic->tabq_coul_FDV0;
 113     ewtabscale       = fr->ic->tabq_scale;
 114     ewtabhalfspace   = 0.5/ewtabscale;
 115
 116     /* Setup water-specific parameters */
 117     inr              = nlist->iinr[0];
 118     iq1              = facel*charge[inr+1];
 119     iq2              = facel*charge[inr+2];
 120     iq3              = facel*charge[inr+3];
 121     vdwioffset0      = 3*nvdwtype*vdwtype[inr+0];
 122
 123     /* When we use explicit cutoffs the value must be identical for elec and VdW, so use elec as an arbitrary choice */
 124     rcutoff          = fr->rcoulomb;
 125     rcutoff2         = rcutoff*rcutoff;
 126
 127     sh_vdw_invrcut6  = fr->ic->sh_invrc6;
 128     rvdw             = fr->rvdw;
 129
 130     outeriter        = 0;
 131     inneriter        = 0;
 132
 133     /* Start outer loop over neighborlists */
 134     for(iidx=0; iidx<nri; iidx++)
 135     {
 136         /* Load shift vector for this list */
 137         i_shift_offset   = DIM*shiftidx[iidx];
 138         shX              = shiftvec[i_shift_offset+XX];
 139         shY              = shiftvec[i_shift_offset+YY];
 140         shZ              = shiftvec[i_shift_offset+ZZ];
 141
 142         /* Load limits for loop over neighbors */
 143         j_index_start    = jindex[iidx];
 144         j_index_end      = jindex[iidx+1];
 145
 146         /* Get outer coordinate index */
 147         inr              = iinr[iidx];
 148         i_coord_offset   = DIM*inr;
 149
 150         /* Load i particle coords and add shift vector */
 151         ix0              = shX + x[i_coord_offset+DIM*0+XX];
 152         iy0              = shY + x[i_coord_offset+DIM*0+YY];
 153         iz0              = shZ + x[i_coord_offset+DIM*0+ZZ];
 154         ix1              = shX + x[i_coord_offset+DIM*1+XX];
 155         iy1              = shY + x[i_coord_offset+DIM*1+YY];
 156         iz1              = shZ + x[i_coord_offset+DIM*1+ZZ];
 157         ix2              = shX + x[i_coord_offset+DIM*2+XX];
 158         iy2              = shY + x[i_coord_offset+DIM*2+YY];
 159         iz2              = shZ + x[i_coord_offset+DIM*2+ZZ];
 160         ix3              = shX + x[i_coord_offset+DIM*3+XX];
 161         iy3              = shY + x[i_coord_offset+DIM*3+YY];
 162         iz3              = shZ + x[i_coord_offset+DIM*3+ZZ];
 163
 164         fix0             = 0.0;
 165         fiy0             = 0.0;
 166         fiz0             = 0.0;
 167         fix1             = 0.0;
 168         fiy1             = 0.0;
 169         fiz1             = 0.0;
 170         fix2             = 0.0;
 171         fiy2             = 0.0;
 172         fiz2             = 0.0;
 173         fix3             = 0.0;
 174         fiy3             = 0.0;
 175         fiz3             = 0.0;
 176
 177         /* Reset potential sums */
 178         velecsum         = 0.0;
 179         vvdwsum          = 0.0;
 180
 181         /* Start inner kernel loop */
 182         for(jidx=j_index_start; jidx<j_index_end; jidx++)
 183         {
 184             /* Get j neighbor index, and coordinate index */
 185             jnr              = jjnr[jidx];
 186             j_coord_offset   = DIM*jnr;
 187
 188             /* load j atom coordinates */
 189             jx0              = x[j_coord_offset+DIM*0+XX];
 190             jy0              = x[j_coord_offset+DIM*0+YY];
 191             jz0              = x[j_coord_offset+DIM*0+ZZ];
 192
 193             /* Calculate displacement vector */
 194             dx00             = ix0 - jx0;
 195             dy00             = iy0 - jy0;
 196             dz00             = iz0 - jz0;
 197             dx10             = ix1 - jx0;
 198             dy10             = iy1 - jy0;
 199             dz10             = iz1 - jz0;
 200             dx20             = ix2 - jx0;
 201             dy20             = iy2 - jy0;
 202             dz20             = iz2 - jz0;
 203             dx30             = ix3 - jx0;
 204             dy30             = iy3 - jy0;
 205             dz30             = iz3 - jz0;
 206
 207             /* Calculate squared distance and things based on it */
 208             rsq00            = dx00*dx00+dy00*dy00+dz00*dz00;
 209             rsq10            = dx10*dx10+dy10*dy10+dz10*dz10;
 210             rsq20            = dx20*dx20+dy20*dy20+dz20*dz20;
 211             rsq30            = dx30*dx30+dy30*dy30+dz30*dz30;
 212
 213             rinv00           = gmx_invsqrt(rsq00);
 214             rinv10           = gmx_invsqrt(rsq10);
 215             rinv20           = gmx_invsqrt(rsq20);
 216             rinv30           = gmx_invsqrt(rsq30);
 217
 218             rinvsq00         = rinv00*rinv00;
 219             rinvsq10         = rinv10*rinv10;
 220             rinvsq20         = rinv20*rinv20;
 221             rinvsq30         = rinv30*rinv30;
 222
 223             /* Load parameters for j particles */
 224             jq0              = charge[jnr+0];
 225             vdwjidx0         = 3*vdwtype[jnr+0];
 226
 227             /**************************
 228              * CALCULATE INTERACTIONS *
 229              **************************/
 230
 231             if (rsq00<rcutoff2)
 232             {
 233
 234             r00              = rsq00*rinv00;
 235
 236             c6_00            = vdwparam[vdwioffset0+vdwjidx0];
 237             cexp1_00         = vdwparam[vdwioffset0+vdwjidx0+1];
 238             cexp2_00         = vdwparam[vdwioffset0+vdwjidx0+2];
 239
 240             /* BUCKINGHAM DISPERSION/REPULSION */
 241             rinvsix          = rinvsq00*rinvsq00*rinvsq00;
 242             vvdw6            = c6_00*rinvsix;
 243             br               = cexp2_00*r00;
 244             vvdwexp          = cexp1_00*exp(-br);
 245             vvdw             = (vvdwexp-cexp1_00*exp(-cexp2_00*rvdw)) - (vvdw6 - c6_00*sh_vdw_invrcut6)*(1.0/6.0);
 246             fvdw             = (br*vvdwexp-vvdw6)*rinvsq00;
 247
 248             /* Update potential sums from outer loop */
 249             vvdwsum         += vvdw;
 250
 251             fscal            = fvdw;
 252
 253             /* Calculate temporary vectorial force */
 254             tx               = fscal*dx00;
 255             ty               = fscal*dy00;
 256             tz               = fscal*dz00;
 257
 258             /* Update vectorial force */
 259             fix0            += tx;
 260             fiy0            += ty;
 261             fiz0            += tz;
 262             f[j_coord_offset+DIM*0+XX] -= tx;
 263             f[j_coord_offset+DIM*0+YY] -= ty;
 264             f[j_coord_offset+DIM*0+ZZ] -= tz;
 265
 266             }
 267
 268             /**************************
 269              * CALCULATE INTERACTIONS *
 270              **************************/
 271
 272             if (rsq10<rcutoff2)
 273             {
 274
 275             r10              = rsq10*rinv10;
 276
 277             qq10             = iq1*jq0;
 278
 279             /* EWALD ELECTROSTATICS */
 280
 281             /* Calculate Ewald table index by multiplying r with scale and truncate to integer */
 282             ewrt             = r10*ewtabscale;
 283             ewitab           = ewrt;
 284             eweps            = ewrt-ewitab;
 285             ewitab           = 4*ewitab;
 286             felec            = ewtab[ewitab]+eweps*ewtab[ewitab+1];
 287             velec            = qq10*((rinv10-sh_ewald)-(ewtab[ewitab+2]-ewtabhalfspace*eweps*(ewtab[ewitab]+felec)));
 288             felec            = qq10*rinv10*(rinvsq10-felec);
 289
 290             /* Update potential sums from outer loop */
 291             velecsum        += velec;
 292
 293             fscal            = felec;
 294
 295             /* Calculate temporary vectorial force */
 296             tx               = fscal*dx10;
 297             ty               = fscal*dy10;
 298             tz               = fscal*dz10;
 299
 300             /* Update vectorial force */
 301             fix1            += tx;
 302             fiy1            += ty;
 303             fiz1            += tz;
 304             f[j_coord_offset+DIM*0+XX] -= tx;
 305             f[j_coord_offset+DIM*0+YY] -= ty;
 306             f[j_coord_offset+DIM*0+ZZ] -= tz;
 307
 308             }
 309
 310             /**************************
 311              * CALCULATE INTERACTIONS *
 312              **************************/
 313
 314             if (rsq20<rcutoff2)
 315             {
 316
 317             r20              = rsq20*rinv20;
 318
 319             qq20             = iq2*jq0;
 320
 321             /* EWALD ELECTROSTATICS */
 322
 323             /* Calculate Ewald table index by multiplying r with scale and truncate to integer */
 324             ewrt             = r20*ewtabscale;
 325             ewitab           = ewrt;
 326             eweps            = ewrt-ewitab;
 327             ewitab           = 4*ewitab;
 328             felec            = ewtab[ewitab]+eweps*ewtab[ewitab+1];
 329             velec            = qq20*((rinv20-sh_ewald)-(ewtab[ewitab+2]-ewtabhalfspace*eweps*(ewtab[ewitab]+felec)));
 330             felec            = qq20*rinv20*(rinvsq20-felec);
 331
 332             /* Update potential sums from outer loop */
 333             velecsum        += velec;
 334
 335             fscal            = felec;
 336
 337             /* Calculate temporary vectorial force */
 338             tx               = fscal*dx20;
 339             ty               = fscal*dy20;
 340             tz               = fscal*dz20;
 341
 342             /* Update vectorial force */
 343             fix2            += tx;
 344             fiy2            += ty;
 345             fiz2            += tz;
 346             f[j_coord_offset+DIM*0+XX] -= tx;
 347             f[j_coord_offset+DIM*0+YY] -= ty;
 348             f[j_coord_offset+DIM*0+ZZ] -= tz;
 349
 350             }
 351
 352             /**************************
 353              * CALCULATE INTERACTIONS *
 354              **************************/
 355
 356             if (rsq30<rcutoff2)
 357             {
 358
 359             r30              = rsq30*rinv30;
 360
 361             qq30             = iq3*jq0;
 362
 363             /* EWALD ELECTROSTATICS */
 364
 365             /* Calculate Ewald table index by multiplying r with scale and truncate to integer */
 366             ewrt             = r30*ewtabscale;
 367             ewitab           = ewrt;
 368             eweps            = ewrt-ewitab;
 369             ewitab           = 4*ewitab;
 370             felec            = ewtab[ewitab]+eweps*ewtab[ewitab+1];
 371             velec            = qq30*((rinv30-sh_ewald)-(ewtab[ewitab+2]-ewtabhalfspace*eweps*(ewtab[ewitab]+felec)));
 372             felec            = qq30*rinv30*(rinvsq30-felec);
 373
 374             /* Update potential sums from outer loop */
 375             velecsum        += velec;
 376
 377             fscal            = felec;
 378
 379             /* Calculate temporary vectorial force */
 380             tx               = fscal*dx30;
 381             ty               = fscal*dy30;
 382             tz               = fscal*dz30;
 383
 384             /* Update vectorial force */
 385             fix3            += tx;
 386             fiy3            += ty;
 387             fiz3            += tz;
 388             f[j_coord_offset+DIM*0+XX] -= tx;
 389             f[j_coord_offset+DIM*0+YY] -= ty;
 390             f[j_coord_offset+DIM*0+ZZ] -= tz;
 391
 392             }
 393
 394             /* Inner loop uses 218 flops */
 395         }
 396         /* End of innermost loop */
 397
 398         tx = ty = tz = 0;
 399         f[i_coord_offset+DIM*0+XX] += fix0;
 400         f[i_coord_offset+DIM*0+YY] += fiy0;
 401         f[i_coord_offset+DIM*0+ZZ] += fiz0;
 402         tx                         += fix0;
 403         ty                         += fiy0;
 404         tz                         += fiz0;
 405         f[i_coord_offset+DIM*1+XX] += fix1;
 406         f[i_coord_offset+DIM*1+YY] += fiy1;
 407         f[i_coord_offset+DIM*1+ZZ] += fiz1;
 408         tx                         += fix1;
 409         ty                         += fiy1;
 410         tz                         += fiz1;
 411         f[i_coord_offset+DIM*2+XX] += fix2;
 412         f[i_coord_offset+DIM*2+YY] += fiy2;
 413         f[i_coord_offset+DIM*2+ZZ] += fiz2;
 414         tx                         += fix2;
 415         ty                         += fiy2;
 416         tz                         += fiz2;
 417         f[i_coord_offset+DIM*3+XX] += fix3;
 418         f[i_coord_offset+DIM*3+YY] += fiy3;
 419         f[i_coord_offset+DIM*3+ZZ] += fiz3;
 420         tx                         += fix3;
 421         ty                         += fiy3;
 422         tz                         += fiz3;
 423         fshift[i_shift_offset+XX]  += tx;
 424         fshift[i_shift_offset+YY]  += ty;
 425         fshift[i_shift_offset+ZZ]  += tz;
 426
 427         ggid                        = gid[iidx];
 428         /* Update potential energies */
 429         kernel_data->energygrp_elec[ggid] += velecsum;
 430         kernel_data->energygrp_vdw[ggid] += vvdwsum;
 431
 432         /* Increment number of inner iterations */
 433         inneriter                  += j_index_end - j_index_start;
 434
 435         /* Outer loop uses 41 flops */
 436     }
 437
 438     /* Increment number of outer iterations */
 439     outeriter        += nri;
 440
 441     /* Update outer/inner flops */
 442
 443     inc_nrnb(nrnb,eNR_NBKERNEL_ELEC_VDW_W4_VF,outeriter*41 + inneriter*218);
 444 }
 445 /*
 446  * Gromacs nonbonded kernel:   nb_kernel_ElecEwSh_VdwBhamSh_GeomW4P1_F_c
 447  * Electrostatics interaction: Ewald
 448  * VdW interaction:            Buckingham
 449  * Geometry:                   Water4-Particle
 450  * Calculate force/pot:        Force
 451  */
 452 void
 453 nb_kernel_ElecEwSh_VdwBhamSh_GeomW4P1_F_c
 454                     (t_nblist                    * gmx_restrict       nlist,
 455                      rvec                        * gmx_restrict          xx,
 456                      rvec                        * gmx_restrict          ff,
 457                      t_forcerec                  * gmx_restrict          fr,
 458                      t_mdatoms                   * gmx_restrict     mdatoms,
 459                      nb_kernel_data_t gmx_unused * gmx_restrict kernel_data,
 460                      t_nrnb                      * gmx_restrict        nrnb)
 461 {
 462     int              i_shift_offset,i_coord_offset,j_coord_offset;
 463     int              j_index_start,j_index_end;
 464     int              nri,inr,ggid,iidx,jidx,jnr,outeriter,inneriter;
 465     real             shX,shY,shZ,tx,ty,tz,fscal,rcutoff,rcutoff2;
 466     int              *iinr,*jindex,*jjnr,*shiftidx,*gid;
 467     real             *shiftvec,*fshift,*x,*f;
 468     int              vdwioffset0;
 469     real             ix0,iy0,iz0,fix0,fiy0,fiz0,iq0,isai0;
 470     int              vdwioffset1;
 471     real             ix1,iy1,iz1,fix1,fiy1,fiz1,iq1,isai1;
 472     int              vdwioffset2;
 473     real             ix2,iy2,iz2,fix2,fiy2,fiz2,iq2,isai2;
 474     int              vdwioffset3;
 475     real             ix3,iy3,iz3,fix3,fiy3,fiz3,iq3,isai3;
 476     int              vdwjidx0;
 477     real             jx0,jy0,jz0,fjx0,fjy0,fjz0,jq0,isaj0;
 478     real             dx00,dy00,dz00,rsq00,rinv00,rinvsq00,r00,qq00,c6_00,c12_00,cexp1_00,cexp2_00;
 479     real             dx10,dy10,dz10,rsq10,rinv10,rinvsq10,r10,qq10,c6_10,c12_10,cexp1_10,cexp2_10;
 480     real             dx20,dy20,dz20,rsq20,rinv20,rinvsq20,r20,qq20,c6_20,c12_20,cexp1_20,cexp2_20;
 481     real             dx30,dy30,dz30,rsq30,rinv30,rinvsq30,r30,qq30,c6_30,c12_30,cexp1_30,cexp2_30;
 482     real             velec,felec,velecsum,facel,crf,krf,krf2;
 483     real             *charge;
 484     int              nvdwtype;
 485     real             rinvsix,rvdw,vvdw,vvdw6,vvdw12,fvdw,fvdw6,fvdw12,vvdwsum,br,vvdwexp,sh_vdw_invrcut6;
 486     int              *vdwtype;
 487     real             *vdwparam;
 488     int              ewitab;
 489     real             ewtabscale,eweps,sh_ewald,ewrt,ewtabhalfspace;
 490     real             *ewtab;
 491
 492     x                = xx[0];
 493     f                = ff[0];
 494
 495     nri              = nlist->nri;
 496     iinr             = nlist->iinr;
 497     jindex           = nlist->jindex;
 498     jjnr             = nlist->jjnr;
 499     shiftidx         = nlist->shift;
 500     gid              = nlist->gid;
 501     shiftvec         = fr->shift_vec[0];
 502     fshift           = fr->fshift[0];
 503     facel            = fr->epsfac;
 504     charge           = mdatoms->chargeA;
 505     nvdwtype         = fr->ntype;
 506     vdwparam         = fr->nbfp;
 507     vdwtype          = mdatoms->typeA;
 508
 509     sh_ewald         = fr->ic->sh_ewald;
 510     ewtab            = fr->ic->tabq_coul_F;
 511     ewtabscale       = fr->ic->tabq_scale;
 512     ewtabhalfspace   = 0.5/ewtabscale;
 513
 514     /* Setup water-specific parameters */
 515     inr              = nlist->iinr[0];
 516     iq1              = facel*charge[inr+1];
 517     iq2              = facel*charge[inr+2];
 518     iq3              = facel*charge[inr+3];
 519     vdwioffset0      = 3*nvdwtype*vdwtype[inr+0];
 520
 521     /* When we use explicit cutoffs the value must be identical for elec and VdW, so use elec as an arbitrary choice */
 522     rcutoff          = fr->rcoulomb;
 523     rcutoff2         = rcutoff*rcutoff;
 524
 525     sh_vdw_invrcut6  = fr->ic->sh_invrc6;
 526     rvdw             = fr->rvdw;
 527
 528     outeriter        = 0;
 529     inneriter        = 0;
 530
 531     /* Start outer loop over neighborlists */
 532     for(iidx=0; iidx<nri; iidx++)
 533     {
 534         /* Load shift vector for this list */
 535         i_shift_offset   = DIM*shiftidx[iidx];
 536         shX              = shiftvec[i_shift_offset+XX];
 537         shY              = shiftvec[i_shift_offset+YY];
 538         shZ              = shiftvec[i_shift_offset+ZZ];
 539
 540         /* Load limits for loop over neighbors */
 541         j_index_start    = jindex[iidx];
 542         j_index_end      = jindex[iidx+1];
 543
 544         /* Get outer coordinate index */
 545         inr              = iinr[iidx];
 546         i_coord_offset   = DIM*inr;
 547
 548         /* Load i particle coords and add shift vector */
 549         ix0              = shX + x[i_coord_offset+DIM*0+XX];
 550         iy0              = shY + x[i_coord_offset+DIM*0+YY];
 551         iz0              = shZ + x[i_coord_offset+DIM*0+ZZ];
 552         ix1              = shX + x[i_coord_offset+DIM*1+XX];
 553         iy1              = shY + x[i_coord_offset+DIM*1+YY];
 554         iz1              = shZ + x[i_coord_offset+DIM*1+ZZ];
 555         ix2              = shX + x[i_coord_offset+DIM*2+XX];
 556         iy2              = shY + x[i_coord_offset+DIM*2+YY];
 557         iz2              = shZ + x[i_coord_offset+DIM*2+ZZ];
 558         ix3              = shX + x[i_coord_offset+DIM*3+XX];
 559         iy3              = shY + x[i_coord_offset+DIM*3+YY];
 560         iz3              = shZ + x[i_coord_offset+DIM*3+ZZ];
 561
 562         fix0             = 0.0;
 563         fiy0             = 0.0;
 564         fiz0             = 0.0;
 565         fix1             = 0.0;
 566         fiy1             = 0.0;
 567         fiz1             = 0.0;
 568         fix2             = 0.0;
 569         fiy2             = 0.0;
 570         fiz2             = 0.0;
 571         fix3             = 0.0;
 572         fiy3             = 0.0;
 573         fiz3             = 0.0;
 574
 575         /* Start inner kernel loop */
 576         for(jidx=j_index_start; jidx<j_index_end; jidx++)
 577         {
 578             /* Get j neighbor index, and coordinate index */
 579             jnr              = jjnr[jidx];
 580             j_coord_offset   = DIM*jnr;
 581
 582             /* load j atom coordinates */
 583             jx0              = x[j_coord_offset+DIM*0+XX];
 584             jy0              = x[j_coord_offset+DIM*0+YY];
 585             jz0              = x[j_coord_offset+DIM*0+ZZ];
 586
 587             /* Calculate displacement vector */
 588             dx00             = ix0 - jx0;
 589             dy00             = iy0 - jy0;
 590             dz00             = iz0 - jz0;
 591             dx10             = ix1 - jx0;
 592             dy10             = iy1 - jy0;
 593             dz10             = iz1 - jz0;
 594             dx20             = ix2 - jx0;
 595             dy20             = iy2 - jy0;
 596             dz20             = iz2 - jz0;
 597             dx30             = ix3 - jx0;
 598             dy30             = iy3 - jy0;
 599             dz30             = iz3 - jz0;
 600
 601             /* Calculate squared distance and things based on it */
 602             rsq00            = dx00*dx00+dy00*dy00+dz00*dz00;
 603             rsq10            = dx10*dx10+dy10*dy10+dz10*dz10;
 604             rsq20            = dx20*dx20+dy20*dy20+dz20*dz20;
 605             rsq30            = dx30*dx30+dy30*dy30+dz30*dz30;
 606
 607             rinv00           = gmx_invsqrt(rsq00);
 608             rinv10           = gmx_invsqrt(rsq10);
 609             rinv20           = gmx_invsqrt(rsq20);
 610             rinv30           = gmx_invsqrt(rsq30);
 611
 612             rinvsq00         = rinv00*rinv00;
 613             rinvsq10         = rinv10*rinv10;
 614             rinvsq20         = rinv20*rinv20;
 615             rinvsq30         = rinv30*rinv30;
 616
 617             /* Load parameters for j particles */
 618             jq0              = charge[jnr+0];
 619             vdwjidx0         = 3*vdwtype[jnr+0];
 620
 621             /**************************
 622              * CALCULATE INTERACTIONS *
 623              **************************/
 624
 625             if (rsq00<rcutoff2)
 626             {
 627
 628             r00              = rsq00*rinv00;
 629
 630             c6_00            = vdwparam[vdwioffset0+vdwjidx0];
 631             cexp1_00         = vdwparam[vdwioffset0+vdwjidx0+1];
 632             cexp2_00         = vdwparam[vdwioffset0+vdwjidx0+2];
 633
 634             /* BUCKINGHAM DISPERSION/REPULSION */
 635             rinvsix          = rinvsq00*rinvsq00*rinvsq00;
 636             vvdw6            = c6_00*rinvsix;
 637             br               = cexp2_00*r00;
 638             vvdwexp          = cexp1_00*exp(-br);
 639             fvdw             = (br*vvdwexp-vvdw6)*rinvsq00;
 640
 641             fscal            = fvdw;
 642
 643             /* Calculate temporary vectorial force */
 644             tx               = fscal*dx00;
 645             ty               = fscal*dy00;
 646             tz               = fscal*dz00;
 647
 648             /* Update vectorial force */
 649             fix0            += tx;
 650             fiy0            += ty;
 651             fiz0            += tz;
 652             f[j_coord_offset+DIM*0+XX] -= tx;
 653             f[j_coord_offset+DIM*0+YY] -= ty;
 654             f[j_coord_offset+DIM*0+ZZ] -= tz;
 655
 656             }
 657
 658             /**************************
 659              * CALCULATE INTERACTIONS *
 660              **************************/
 661
 662             if (rsq10<rcutoff2)
 663             {
 664
 665             r10              = rsq10*rinv10;
 666
 667             qq10             = iq1*jq0;
 668
 669             /* EWALD ELECTROSTATICS */
 670
 671             /* Calculate Ewald table index by multiplying r with scale and truncate to integer */
 672             ewrt             = r10*ewtabscale;
 673             ewitab           = ewrt;
 674             eweps            = ewrt-ewitab;
 675             felec            = (1.0-eweps)*ewtab[ewitab]+eweps*ewtab[ewitab+1];
 676             felec            = qq10*rinv10*(rinvsq10-felec);
 677
 678             fscal            = felec;
 679
 680             /* Calculate temporary vectorial force */
 681             tx               = fscal*dx10;
 682             ty               = fscal*dy10;
 683             tz               = fscal*dz10;
 684
 685             /* Update vectorial force */
 686             fix1            += tx;
 687             fiy1            += ty;
 688             fiz1            += tz;
 689             f[j_coord_offset+DIM*0+XX] -= tx;
 690             f[j_coord_offset+DIM*0+YY] -= ty;
 691             f[j_coord_offset+DIM*0+ZZ] -= tz;
 692
 693             }
 694
 695             /**************************
 696              * CALCULATE INTERACTIONS *
 697              **************************/
 698
 699             if (rsq20<rcutoff2)
 700             {
 701
 702             r20              = rsq20*rinv20;
 703
 704             qq20             = iq2*jq0;
 705
 706             /* EWALD ELECTROSTATICS */
 707
 708             /* Calculate Ewald table index by multiplying r with scale and truncate to integer */
 709             ewrt             = r20*ewtabscale;
 710             ewitab           = ewrt;
 711             eweps            = ewrt-ewitab;
 712             felec            = (1.0-eweps)*ewtab[ewitab]+eweps*ewtab[ewitab+1];
 713             felec            = qq20*rinv20*(rinvsq20-felec);
 714
 715             fscal            = felec;
 716
 717             /* Calculate temporary vectorial force */
 718             tx               = fscal*dx20;
 719             ty               = fscal*dy20;
 720             tz               = fscal*dz20;
 721
 722             /* Update vectorial force */
 723             fix2            += tx;
 724             fiy2            += ty;
 725             fiz2            += tz;
 726             f[j_coord_offset+DIM*0+XX] -= tx;
 727             f[j_coord_offset+DIM*0+YY] -= ty;
 728             f[j_coord_offset+DIM*0+ZZ] -= tz;
 729
 730             }
 731
 732             /**************************
 733              * CALCULATE INTERACTIONS *
 734              **************************/
 735
 736             if (rsq30<rcutoff2)
 737             {
 738
 739             r30              = rsq30*rinv30;
 740
 741             qq30             = iq3*jq0;
 742
 743             /* EWALD ELECTROSTATICS */
 744
 745             /* Calculate Ewald table index by multiplying r with scale and truncate to integer */
 746             ewrt             = r30*ewtabscale;
 747             ewitab           = ewrt;
 748             eweps            = ewrt-ewitab;
 749             felec            = (1.0-eweps)*ewtab[ewitab]+eweps*ewtab[ewitab+1];
 750             felec            = qq30*rinv30*(rinvsq30-felec);
 751
 752             fscal            = felec;
 753
 754             /* Calculate temporary vectorial force */
 755             tx               = fscal*dx30;
 756             ty               = fscal*dy30;
 757             tz               = fscal*dz30;
 758
 759             /* Update vectorial force */
 760             fix3            += tx;
 761             fiy3            += ty;
 762             fiz3            += tz;
 763             f[j_coord_offset+DIM*0+XX] -= tx;
 764             f[j_coord_offset+DIM*0+YY] -= ty;
 765             f[j_coord_offset+DIM*0+ZZ] -= tz;
 766
 767             }
 768
 769             /* Inner loop uses 160 flops */
 770         }
 771         /* End of innermost loop */
 772
 773         tx = ty = tz = 0;
 774         f[i_coord_offset+DIM*0+XX] += fix0;
 775         f[i_coord_offset+DIM*0+YY] += fiy0;
 776         f[i_coord_offset+DIM*0+ZZ] += fiz0;
 777         tx                         += fix0;
 778         ty                         += fiy0;
 779         tz                         += fiz0;
 780         f[i_coord_offset+DIM*1+XX] += fix1;
 781         f[i_coord_offset+DIM*1+YY] += fiy1;
 782         f[i_coord_offset+DIM*1+ZZ] += fiz1;
 783         tx                         += fix1;
 784         ty                         += fiy1;
 785         tz                         += fiz1;
 786         f[i_coord_offset+DIM*2+XX] += fix2;
 787         f[i_coord_offset+DIM*2+YY] += fiy2;
 788         f[i_coord_offset+DIM*2+ZZ] += fiz2;
 789         tx                         += fix2;
 790         ty                         += fiy2;
 791         tz                         += fiz2;
 792         f[i_coord_offset+DIM*3+XX] += fix3;
 793         f[i_coord_offset+DIM*3+YY] += fiy3;
 794         f[i_coord_offset+DIM*3+ZZ] += fiz3;
 795         tx                         += fix3;
 796         ty                         += fiy3;
 797         tz                         += fiz3;
 798         fshift[i_shift_offset+XX]  += tx;
 799         fshift[i_shift_offset+YY]  += ty;
 800         fshift[i_shift_offset+ZZ]  += tz;
 801
 802         /* Increment number of inner iterations */
 803         inneriter                  += j_index_end - j_index_start;
 804
 805         /* Outer loop uses 39 flops */
 806     }
 807
 808     /* Increment number of outer iterations */
 809     outeriter        += nri;
 810
 811     /* Update outer/inner flops */
 812
 813     inc_nrnb(nrnb,eNR_NBKERNEL_ELEC_VDW_W4_F,outeriter*39 + inneriter*160);
 814 }