Bug Summary

File:gromacs/gmxlib/ewald_util.c
Location:line 434, column 29
Description:Value stored to 'fscal' is never read

Annotated Source Code

1/*
2 * This file is part of the GROMACS molecular simulation package.
3 *
4 * Copyright (c) 1991-2000, University of Groningen, The Netherlands.
5 * Copyright (c) 2001-2004, The GROMACS development team.
6 * Copyright (c) 2013,2014, by the GROMACS development team, led by
7 * Mark Abraham, David van der Spoel, Berk Hess, and Erik Lindahl,
8 * and including many others, as listed in the AUTHORS file in the
9 * top-level source directory and at http://www.gromacs.org.
10 *
11 * GROMACS is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU Lesser General Public License
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21 * You should have received a copy of the GNU Lesser General Public
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28 * control is crucial - bugs must be traceable. We will be happy to
29 * consider code for inclusion in the official distribution, but
30 * derived work must not be called official GROMACS. Details are found
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36 */
37#ifdef HAVE_CONFIG_H1
38#include <config.h>
39#endif
40
41#include <stdio.h>
42#include <math.h>
43#include "gromacs/math/utilities.h"
44#include "typedefs.h"
45#include "types/commrec.h"
46#include "gromacs/math/vec.h"
47#include "coulomb.h"
48#include "gromacs/utility/smalloc.h"
49#include "physics.h"
50#include "txtdump.h"
51#include "gromacs/utility/futil.h"
52#include "names.h"
53#include "macros.h"
54
55real calc_ewaldcoeff_q(real rc, real dtol)
56{
57 real x = 5, low, high;
58 int n, i = 0;
59
60
61 do
62 {
63 i++;
64 x *= 2;
65 }
66 while (gmx_erfc(x*rc)gmx_erfcf(x*rc) > dtol);
67
68 n = i+60; /* search tolerance is 2^-60 */
69 low = 0;
70 high = x;
71 for (i = 0; i < n; i++)
72 {
73 x = (low+high)/2;
74 if (gmx_erfc(x*rc)gmx_erfcf(x*rc) > dtol)
75 {
76 low = x;
77 }
78 else
79 {
80 high = x;
81 }
82 }
83 return x;
84}
85
86static real ewald_function_lj(real x, real rc)
87{
88 real xrc, xrc2, xrc4, factor;
89 xrc = x*rc;
90 xrc2 = xrc*xrc;
91 xrc4 = xrc2*xrc2;
92#ifdef GMX_DOUBLE
93 factor = exp(-xrc2)*(1 + xrc2 + xrc4/2.0);
94#else
95 factor = expf(-xrc2)*(1 + xrc2 + xrc4/2.0);
96#endif
97
98 return factor;
99}
100
101real calc_ewaldcoeff_lj(real rc, real dtol)
102{
103 real x = 5, low, high;
104 int n, i = 0;
105
106 do
107 {
108 i++;
109 x *= 2.0;
110 }
111 while (ewald_function_lj(x, rc) > dtol);
112
113 n = i + 60; /* search tolerance is 2^-60 */
114 low = 0;
115 high = x;
116 for (i = 0; i < n; ++i)
117 {
118 x = (low + high) / 2.0;
119 if (ewald_function_lj(x, rc) > dtol)
120 {
121 low = x;
122 }
123 else
124 {
125 high = x;
126 }
127 }
128 return x;
129}
130
131void ewald_LRcorrection(int start, int end,
132 t_commrec *cr, int thread, t_forcerec *fr,
133 real *chargeA, real *chargeB,
134 real *C6A, real *C6B,
135 real *sigmaA, real *sigmaB,
136 real *sigma3A, real *sigma3B,
137 gmx_bool calc_excl_corr,
138 t_blocka *excl, rvec x[],
139 matrix box, rvec mu_tot[],
140 int ewald_geometry, real epsilon_surface,
141 rvec *f, tensor vir_q, tensor vir_lj,
142 real *Vcorr_q, real *Vcorr_lj,
143 real lambda_q, real lambda_lj,
144 real *dvdlambda_q, real *dvdlambda_lj)
145{
146 int i, i1, i2, j, k, m, iv, jv, q;
147 atom_id *AA;
148 double Vexcl_q, dvdl_excl_q, dvdl_excl_lj; /* Necessary for precision */
149 double Vexcl_lj;
150 real one_4pi_eps;
151 real v, vc, qiA, qiB, dr2, rinv, enercorr;
152 real Vself_q[2], Vself_lj[2], Vdipole[2], rinv2, ewc_q = fr->ewaldcoeff_q, ewcdr;
153 real ewc_lj = fr->ewaldcoeff_lj, ewc_lj2 = ewc_lj * ewc_lj;
154 real c6Ai = 0, c6Bi = 0, c6A = 0, c6B = 0, ewcdr2, ewcdr4, c6L = 0, rinv6;
155 rvec df, dx, mutot[2], dipcorrA, dipcorrB;
156 tensor dxdf_q, dxdf_lj;
157 real vol = box[XX0][XX0]*box[YY1][YY1]*box[ZZ2][ZZ2];
158 real L1_q, L1_lj, dipole_coeff, qqA, qqB, qqL, vr0_q, vr0_lj = 0;
159 gmx_bool bFreeEnergy = (chargeB != NULL((void*)0));
160 gmx_bool bMolPBC = fr->bMolPBC;
161 gmx_bool bDoingLBRule = (fr->ljpme_combination_rule == eljpmeLB);
162
163 /* This routine can be made faster by using tables instead of analytical interactions
164 * However, that requires a thorough verification that they are correct in all cases.
165 */
166
167 one_4pi_eps = ONE_4PI_EPS0((332.0636930*(4.184))*0.1)/fr->epsilon_r;
168 vr0_q = ewc_q*M_2_SQRTPI1.12837916709551257390;
169 if (EVDW_PME(fr->vdwtype)((fr->vdwtype) == evdwPME))
170 {
171 vr0_lj = -pow(ewc_lj, 6)/6.0;
172 }
173
174 AA = excl->a;
175 Vexcl_q = 0;
176 Vexcl_lj = 0;
177 dvdl_excl_q = 0;
178 dvdl_excl_lj = 0;
179 Vdipole[0] = 0;
180 Vdipole[1] = 0;
181 L1_q = 1.0-lambda_q;
182 L1_lj = 1.0-lambda_lj;
183 /* Note that we have to transform back to gromacs units, since
184 * mu_tot contains the dipole in debye units (for output).
185 */
186 for (i = 0; (i < DIM3); i++)
187 {
188 mutot[0][i] = mu_tot[0][i]*DEBYE2ENM0.02081941;
189 mutot[1][i] = mu_tot[1][i]*DEBYE2ENM0.02081941;
190 dipcorrA[i] = 0;
191 dipcorrB[i] = 0;
192 }
193 dipole_coeff = 0;
194 switch (ewald_geometry)
195 {
196 case eewg3D:
197 if (epsilon_surface != 0)
198 {
199 dipole_coeff =
200 2*M_PI3.14159265358979323846*ONE_4PI_EPS0((332.0636930*(4.184))*0.1)/((2*epsilon_surface + fr->epsilon_r)*vol);
201 for (i = 0; (i < DIM3); i++)
202 {
203 dipcorrA[i] = 2*dipole_coeff*mutot[0][i];
204 dipcorrB[i] = 2*dipole_coeff*mutot[1][i];
205 }
206 }
207 break;
208 case eewg3DC:
209 dipole_coeff = 2*M_PI3.14159265358979323846*one_4pi_eps/vol;
210 dipcorrA[ZZ2] = 2*dipole_coeff*mutot[0][ZZ2];
211 dipcorrB[ZZ2] = 2*dipole_coeff*mutot[1][ZZ2];
212 break;
213 default:
214 gmx_incons("Unsupported Ewald geometry")_gmx_error("incons", "Unsupported Ewald geometry", "/home/alexxy/Develop/gromacs/src/gromacs/gmxlib/ewald_util.c"
, 214);
215 break;
216 }
217 if (debug)
218 {
219 fprintf(debug, "dipcorr = %8.3f %8.3f %8.3f\n",
220 dipcorrA[XX0], dipcorrA[YY1], dipcorrA[ZZ2]);
221 fprintf(debug, "mutot = %8.3f %8.3f %8.3f\n",
222 mutot[0][XX0], mutot[0][YY1], mutot[0][ZZ2]);
223 }
224 clear_mat(dxdf_q);
225 if (EVDW_PME(fr->vdwtype)((fr->vdwtype) == evdwPME))
226 {
227 clear_mat(dxdf_lj);
228 }
229 if ((calc_excl_corr || dipole_coeff != 0 || EVDW_PME(fr->vdwtype)((fr->vdwtype) == evdwPME)) && !bFreeEnergy)
230 {
231 for (i = start; (i < end); i++)
232 {
233 /* Initiate local variables (for this i-particle) to 0 */
234 qiA = chargeA[i]*one_4pi_eps;
235 if (EVDW_PME(fr->vdwtype)((fr->vdwtype) == evdwPME))
236 {
237 c6Ai = C6A[i];
238 if (bDoingLBRule)
239 {
240 c6Ai *= sigma3A[i];
241 }
242 }
243 if (calc_excl_corr)
244 {
245 i1 = excl->index[i];
246 i2 = excl->index[i+1];
247
248 /* Loop over excluded neighbours */
249 for (j = i1; (j < i2); j++)
250 {
251 k = AA[j];
252 /*
253 * First we must test whether k <> i, and then,
254 * because the exclusions are all listed twice i->k
255 * and k->i we must select just one of the two. As
256 * a minor optimization we only compute forces when
257 * the charges are non-zero.
258 */
259 if (k > i)
260 {
261 qqA = qiA*chargeA[k];
262 if (EVDW_PME(fr->vdwtype)((fr->vdwtype) == evdwPME))
263 {
264 c6A = c6Ai * C6A[k];
265 if (bDoingLBRule)
266 {
267 c6A *= pow(0.5*(sigmaA[i]+sigmaA[k]), 6)*sigma3A[k];
268 }
269 }
270 if (qqA != 0.0 || c6A != 0.0)
271 {
272 real fscal;
273
274 fscal = 0;
275 rvec_sub(x[i], x[k], dx);
276 if (bMolPBC)
277 {
278 /* Cheap pbc_dx, assume excluded pairs are at short distance. */
279 for (m = DIM3-1; (m >= 0); m--)
280 {
281 if (dx[m] > 0.5*box[m][m])
282 {
283 rvec_dec(dx, box[m]);
284 }
285 else if (dx[m] < -0.5*box[m][m])
286 {
287 rvec_inc(dx, box[m]);
288 }
289 }
290 }
291 dr2 = norm2(dx);
292 /* Distance between two excluded particles
293 * may be zero in the case of shells
294 */
295 if (dr2 != 0)
296 {
297 rinv = gmx_invsqrt(dr2)gmx_software_invsqrt(dr2);
298 rinv2 = rinv*rinv;
299 if (qqA != 0.0)
300 {
301 real dr;
302
303 dr = 1.0/rinv;
304 ewcdr = ewc_q*dr;
305 vc = qqA*gmx_erf(ewcdr)gmx_erff(ewcdr)*rinv;
306 Vexcl_q += vc;
307#ifdef GMX_DOUBLE
308 /* Relative accuracy at R_ERF_R_INACC of 3e-10 */
309#define R_ERF_R_INACC0.1 0.006
310#else
311 /* Relative accuracy at R_ERF_R_INACC of 2e-5 */
312#define R_ERF_R_INACC0.1 0.1
313#endif
314 /* fscal is the scalar force pre-multiplied by rinv,
315 * to normalise the relative position vector dx */
316 if (ewcdr > R_ERF_R_INACC0.1)
317 {
318 fscal = rinv2*(vc - qqA*ewc_q*M_2_SQRTPI1.12837916709551257390*exp(-ewcdr*ewcdr));
319 }
320 else
321 {
322 /* Use a fourth order series expansion for small ewcdr */
323 fscal = ewc_q*ewc_q*qqA*vr0_q*(2.0/3.0 - 0.4*ewcdr*ewcdr);
324 }
325
326 /* The force vector is obtained by multiplication with
327 * the relative position vector
328 */
329 svmul(fscal, dx, df);
330 rvec_inc(f[k], df);
331 rvec_dec(f[i], df);
332 for (iv = 0; (iv < DIM3); iv++)
333 {
334 for (jv = 0; (jv < DIM3); jv++)
335 {
336 dxdf_q[iv][jv] += dx[iv]*df[jv];
337 }
338 }
339 }
340
341 if (c6A != 0.0)
342 {
343 rinv6 = rinv2*rinv2*rinv2;
344 ewcdr2 = ewc_lj2*dr2;
345 ewcdr4 = ewcdr2*ewcdr2;
346 /* We get the excluded long-range contribution from -C6*(1-g(r))
347 * g(r) is also defined in the manual under LJ-PME
348 */
349 vc = -c6A*rinv6*(1.0 - exp(-ewcdr2)*(1 + ewcdr2 + 0.5*ewcdr4));
350 Vexcl_lj += vc;
351 /* The force is the derivative of the potential vc.
352 * fscal is the scalar force pre-multiplied by rinv,
353 * to normalise the relative position vector dx */
354 fscal = 6.0*vc*rinv2 + c6A*rinv6*exp(-ewcdr2)*ewc_lj2*ewcdr4;
355
356 /* The force vector is obtained by multiplication with
357 * the relative position vector
358 */
359 svmul(fscal, dx, df);
360 rvec_inc(f[k], df);
361 rvec_dec(f[i], df);
362 for (iv = 0; (iv < DIM3); iv++)
363 {
364 for (jv = 0; (jv < DIM3); jv++)
365 {
366 dxdf_lj[iv][jv] += dx[iv]*df[jv];
367 }
368 }
369 }
370 }
371 else
372 {
373 Vexcl_q += qqA*vr0_q;
374 Vexcl_lj += c6A*vr0_lj;
375 }
376 }
377 }
378 }
379 }
380 /* Dipole correction on force */
381 if (dipole_coeff != 0)
382 {
383 for (j = 0; (j < DIM3); j++)
384 {
385 f[i][j] -= dipcorrA[j]*chargeA[i];
386 }
387 }
388 }
389 }
390 else if (calc_excl_corr || dipole_coeff != 0 || EVDW_PME(fr->vdwtype)((fr->vdwtype) == evdwPME))
391 {
392 for (i = start; (i < end); i++)
393 {
394 /* Initiate local variables (for this i-particle) to 0 */
395 qiA = chargeA[i]*one_4pi_eps;
396 qiB = chargeB[i]*one_4pi_eps;
397 if (EVDW_PME(fr->vdwtype)((fr->vdwtype) == evdwPME))
398 {
399 c6Ai = C6A[i];
400 c6Bi = C6B[i];
401 if (bDoingLBRule)
402 {
403 c6Ai *= sigma3A[i];
404 c6Bi *= sigma3B[i];
405 }
406 }
407 if (calc_excl_corr)
408 {
409 i1 = excl->index[i];
410 i2 = excl->index[i+1];
411
412 /* Loop over excluded neighbours */
413 for (j = i1; (j < i2); j++)
414 {
415 k = AA[j];
416 if (k > i)
417 {
418 qqA = qiA*chargeA[k];
419 qqB = qiB*chargeB[k];
420 if (EVDW_PME(fr->vdwtype)((fr->vdwtype) == evdwPME))
421 {
422 c6A = c6Ai*C6A[k];
423 c6B = c6Bi*C6B[k];
424 if (bDoingLBRule)
425 {
426 c6A *= pow(0.5*(sigmaA[i]+sigmaA[k]), 6)*sigma3A[k];
427 c6B *= pow(0.5*(sigmaB[i]+sigmaB[k]), 6)*sigma3B[k];
428 }
429 }
430 if (qqA != 0.0 || qqB != 0.0 || c6A != 0.0 || c6B != 0.0)
431 {
432 real fscal;
433
434 fscal = 0;
Value stored to 'fscal' is never read
435 qqL = L1_q*qqA + lambda_q*qqB;
436 if (EVDW_PME(fr->vdwtype)((fr->vdwtype) == evdwPME))
437 {
438 c6L = L1_lj*c6A + lambda_lj*c6B;
439 }
440 rvec_sub(x[i], x[k], dx);
441 if (bMolPBC)
442 {
443 /* Cheap pbc_dx, assume excluded pairs are at short distance. */
444 for (m = DIM3-1; (m >= 0); m--)
445 {
446 if (dx[m] > 0.5*box[m][m])
447 {
448 rvec_dec(dx, box[m]);
449 }
450 else if (dx[m] < -0.5*box[m][m])
451 {
452 rvec_inc(dx, box[m]);
453 }
454 }
455 }
456 dr2 = norm2(dx);
457 if (dr2 != 0)
458 {
459 rinv = gmx_invsqrt(dr2)gmx_software_invsqrt(dr2);
460 rinv2 = rinv*rinv;
461 if (qqA != 0.0 || qqB != 0.0)
462 {
463 real dr;
464
465 dr = 1.0/rinv;
466 v = gmx_erf(ewc_q*dr)gmx_erff(ewc_q*dr)*rinv;
467 vc = qqL*v;
468 Vexcl_q += vc;
469 /* fscal is the scalar force pre-multiplied by rinv,
470 * to normalise the relative position vector dx */
471 fscal = rinv2*(vc-qqL*ewc_q*M_2_SQRTPI1.12837916709551257390*exp(-ewc_q*ewc_q*dr2));
472 dvdl_excl_q += (qqB - qqA)*v;
473
474 /* The force vector is obtained by multiplication with
475 * the relative position vector
476 */
477 svmul(fscal, dx, df);
478 rvec_inc(f[k], df);
479 rvec_dec(f[i], df);
480 for (iv = 0; (iv < DIM3); iv++)
481 {
482 for (jv = 0; (jv < DIM3); jv++)
483 {
484 dxdf_q[iv][jv] += dx[iv]*df[jv];
485 }
486 }
487 }
488
489 if ((c6A != 0.0 || c6B != 0.0) && EVDW_PME(fr->vdwtype)((fr->vdwtype) == evdwPME))
490 {
491 rinv6 = rinv2*rinv2*rinv2;
492 ewcdr2 = ewc_lj2*dr2;
493 ewcdr4 = ewcdr2*ewcdr2;
494 v = -rinv6*(1.0 - exp(-ewcdr2)*(1 + ewcdr2 + 0.5*ewcdr4));
495 vc = c6L*v;
496 Vexcl_lj += vc;
497 /* fscal is the scalar force pre-multiplied by rinv,
498 * to normalise the relative position vector dx */
499 fscal = 6.0*vc*rinv2 + c6L*rinv6*exp(-ewcdr2)*ewc_lj2*ewcdr4;
500 dvdl_excl_lj += (c6B - c6A)*v;
501
502 /* The force vector is obtained by multiplication with
503 * the relative position vector
504 */
505 svmul(fscal, dx, df);
506 rvec_inc(f[k], df);
507 rvec_dec(f[i], df);
508 for (iv = 0; (iv < DIM3); iv++)
509 {
510 for (jv = 0; (jv < DIM3); jv++)
511 {
512 dxdf_lj[iv][jv] += dx[iv]*df[jv];
513 }
514 }
515 }
516 }
517 else
518 {
519 Vexcl_q += qqL*vr0_q;
520 dvdl_excl_q += (qqB - qqA)*vr0_q;
521 Vexcl_lj += c6L*vr0_lj;
522 dvdl_excl_lj += (c6B - c6A)*vr0_lj;
523 }
524 }
525 }
526 }
527 }
528 /* Dipole correction on force */
529 if (dipole_coeff != 0)
530 {
531 for (j = 0; (j < DIM3); j++)
532 {
533 f[i][j] -= L1_q*dipcorrA[j]*chargeA[i]
534 + lambda_q*dipcorrB[j]*chargeB[i];
535 }
536 }
537 }
538 }
539 for (iv = 0; (iv < DIM3); iv++)
540 {
541 for (jv = 0; (jv < DIM3); jv++)
542 {
543 vir_q[iv][jv] += 0.5*dxdf_q[iv][jv];
544 vir_lj[iv][jv] += 0.5*dxdf_lj[iv][jv];
545 }
546 }
547
548 Vself_q[0] = 0;
549 Vself_q[1] = 0;
550 Vself_lj[0] = 0;
551 Vself_lj[1] = 0;
552
553 /* Global corrections only on master process */
554 if (MASTER(cr)(((cr)->nodeid == 0) || !((cr)->nnodes > 1)) && thread == 0)
555 {
556 for (q = 0; q < (bFreeEnergy ? 2 : 1); q++)
557 {
558 if (calc_excl_corr)
559 {
560 /* Self-energy correction */
561 Vself_q[q] = ewc_q*one_4pi_eps*fr->q2sum[q]*M_1_SQRTPI0.564189583547756;
562 if (EVDW_PME(fr->vdwtype)((fr->vdwtype) == evdwPME))
563 {
564 Vself_lj[q] = fr->c6sum[q]*0.5*vr0_lj;
565 }
566 }
567
568 /* Apply surface dipole correction:
569 * correction = dipole_coeff * (dipole)^2
570 */
571 if (dipole_coeff != 0)
572 {
573 if (ewald_geometry == eewg3D)
574 {
575 Vdipole[q] = dipole_coeff*iprod(mutot[q], mutot[q]);
576 }
577 else if (ewald_geometry == eewg3DC)
578 {
579 Vdipole[q] = dipole_coeff*mutot[q][ZZ2]*mutot[q][ZZ2];
580 }
581 }
582 }
583 }
584 if (!bFreeEnergy)
585 {
586 *Vcorr_q = Vdipole[0] - Vself_q[0] - Vexcl_q;
587 if (EVDW_PME(fr->vdwtype)((fr->vdwtype) == evdwPME))
588 {
589 *Vcorr_lj = -Vself_lj[0] - Vexcl_lj;
590 }
591 }
592 else
593 {
594 *Vcorr_q = L1_q*(Vdipole[0] - Vself_q[0])
595 + lambda_q*(Vdipole[1] - Vself_q[1])
596 - Vexcl_q;
597 *dvdlambda_q += Vdipole[1] - Vself_q[1]
598 - (Vdipole[0] - Vself_q[0]) - dvdl_excl_q;
599 if (EVDW_PME(fr->vdwtype)((fr->vdwtype) == evdwPME))
600 {
601 *Vcorr_lj = -(L1_lj*Vself_lj[0] + lambda_lj*Vself_lj[1]) - Vexcl_lj;
602 *dvdlambda_lj += -Vself_lj[1] + Vself_lj[0] - dvdl_excl_lj;
603 }
604 }
605
606 if (debug)
607 {
608 fprintf(debug, "Long Range corrections for Ewald interactions:\n");
609 fprintf(debug, "start=%d,natoms=%d\n", start, end-start);
610 fprintf(debug, "q2sum = %g, Vself_q=%g c6sum = %g, Vself_lj=%g\n",
611 L1_q*fr->q2sum[0]+lambda_q*fr->q2sum[1], L1_q*Vself_q[0]+lambda_q*Vself_q[1], L1_lj*fr->c6sum[0]+lambda_lj*fr->c6sum[1], L1_lj*Vself_lj[0]+lambda_lj*Vself_lj[1]);
612 fprintf(debug, "Electrostatic Long Range correction: Vexcl=%g\n", Vexcl_q);
613 fprintf(debug, "Lennard-Jones Long Range correction: Vexcl=%g\n", Vexcl_lj);
614 if (MASTER(cr)(((cr)->nodeid == 0) || !((cr)->nnodes > 1)) && thread == 0)
615 {
616 if (epsilon_surface > 0 || ewald_geometry == eewg3DC)
617 {
618 fprintf(debug, "Total dipole correction: Vdipole=%g\n",
619 L1_q*Vdipole[0]+lambda_q*Vdipole[1]);
620 }
621 }
622 }
623}
624
625real ewald_charge_correction(t_commrec *cr, t_forcerec *fr, real lambda,
626 matrix box,
627 real *dvdlambda, tensor vir)
628
629{
630 real vol, fac, qs2A, qs2B, vc, enercorr;
631 int d;
632
633 if (MASTER(cr)(((cr)->nodeid == 0) || !((cr)->nnodes > 1)))
634 {
635 /* Apply charge correction */
636 vol = box[XX0][XX0]*box[YY1][YY1]*box[ZZ2][ZZ2];
637
638 fac = M_PI3.14159265358979323846*ONE_4PI_EPS0((332.0636930*(4.184))*0.1)/(fr->epsilon_r*2.0*vol*vol*sqr(fr->ewaldcoeff_q));
639
640 qs2A = fr->qsum[0]*fr->qsum[0];
641 qs2B = fr->qsum[1]*fr->qsum[1];
642
643 vc = (qs2A*(1 - lambda) + qs2B*lambda)*fac;
644
645 enercorr = -vol*vc;
646
647 *dvdlambda += -vol*(qs2B - qs2A)*fac;
648
649 for (d = 0; d < DIM3; d++)
650 {
651 vir[d][d] += vc;
652 }
653
654 if (debug)
655 {
656 fprintf(debug, "Total charge correction: Vcharge=%g\n", enercorr);
657 }
658 }
659 else
660 {
661 enercorr = 0;
662 }
663
664 return enercorr;
665}