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40 #include "forcetable.h"
44 #include "gromacs/fileio/xvgr.h"
45 #include "gromacs/math/functions.h"
46 #include "gromacs/math/multidimarray.h"
47 #include "gromacs/math/units.h"
48 #include "gromacs/math/utilities.h"
49 #include "gromacs/mdspan/extensions.h"
50 #include "gromacs/mdtypes/fcdata.h"
51 #include "gromacs/mdtypes/interaction_const.h"
52 #include "gromacs/utility/arrayref.h"
53 #include "gromacs/utility/cstringutil.h"
54 #include "gromacs/utility/fatalerror.h"
55 #include "gromacs/utility/futil.h"
57 /* All the possible (implemented) table functions */
81 /** Evaluates to true if the table type contains user data. */
82 #define ETAB_USER(e) ((e) == etabUSER || (e) == etabEwaldUser || (e) == etabEwaldUserSwitch)
90 /* This structure holds name and a flag that tells whether
91 this is a Coulomb type funtion */
92 static const t_tab_props tprops[etabNR] = {
93 { "LJ6", FALSE }, { "LJ12", FALSE }, { "LJ6Shift", FALSE },
94 { "LJ12Shift", FALSE }, { "Shift", TRUE }, { "RF", TRUE },
95 { "RF-zero", TRUE }, { "COUL", TRUE }, { "Ewald", TRUE },
96 { "Ewald-Switch", TRUE }, { "Ewald-User", TRUE }, { "Ewald-User-Switch", TRUE },
97 { "LJ6Ewald", FALSE }, { "LJ6Switch", FALSE }, { "LJ12Switch", FALSE },
98 { "COULSwitch", TRUE }, { "EXPMIN", FALSE }, { "USER", FALSE },
103 t_tabledata() = default;
104 t_tabledata(int n, int firstTableNum, double scale, bool bAlloc);
108 std::vector<double> x;
109 std::vector<double> v;
110 std::vector<double> f;
113 double v_q_ewald_lr(double beta, double r)
117 return beta * 2 / sqrt(M_PI);
121 return std::erf(beta * r) / r;
125 double v_lj_ewald_lr(double beta, double r)
127 double br, br2, br4, r6, factor;
130 return gmx::power6(beta) / 6;
138 factor = (1.0 - std::exp(-br2) * (1 + br2 + 0.5 * br4)) / r6;
143 EwaldCorrectionTables generateEwaldCorrectionTables(const int numPoints,
144 const double tableScaling,
146 real_space_grid_contribution_computer v_lr)
151 gmx_bool bOutOfRange;
152 double v_r0, v_r1, v_inrange, vi, a0, a1, a2dx;
155 /* This function is called using either v_ewald_lr or v_lj_ewald_lr as a function argument
156 * depending on wether we should create electrostatic or Lennard-Jones Ewald tables.
161 gmx_fatal(FARGS, "Can not make a spline table with less than 2 points");
164 const double dx = 1 / tableScaling;
166 EwaldCorrectionTables tables;
167 tables.scale = tableScaling;
168 tables.tableF.resize(numPoints);
169 tables.tableV.resize(numPoints);
170 tables.tableFDV0.resize(numPoints * 4);
171 gmx::ArrayRef<real> table_f = tables.tableF;
172 gmx::ArrayRef<real> table_v = tables.tableV;
173 gmx::ArrayRef<real> table_fdv0 = tables.tableFDV0;
175 /* We need some margin to be able to divide table values by r
176 * in the kernel and also to do the integration arithmetics
177 * without going out of range. Furthemore, we divide by dx below.
179 tab_max = GMX_REAL_MAX * 0.0001;
181 /* This function produces a table with:
182 * maximum energy error: V'''/(6*12*sqrt(3))*dx^3
183 * maximum force error: V'''/(6*4)*dx^2
184 * The rms force error is the max error times 1/sqrt(5)=0.45.
188 i_inrange = numPoints;
191 for (i = numPoints - 1; i >= 0; i--)
195 v_r0 = (*v_lr)(beta, x_r0);
206 /* Linear continuation for the last point in range */
207 vi = v_inrange - dc * (i - i_inrange) * dx;
217 /* Get the potential at table point i-1 */
218 v_r1 = (*v_lr)(beta, (i - 1) * dx);
220 if (v_r1 != v_r1 || v_r1 < -tab_max || v_r1 > tab_max)
227 /* Calculate the average second derivative times dx over interval i-1 to i.
228 * Using the function values at the end points and in the middle.
230 a2dx = (v_r0 + v_r1 - 2 * (*v_lr)(beta, x_r0 - 0.5 * dx)) / (0.25 * dx);
231 /* Set the derivative of the spline to match the difference in potential
232 * over the interval plus the average effect of the quadratic term.
233 * This is the essential step for minimizing the error in the force.
235 dc = (v_r0 - v_r1) / dx + 0.5 * a2dx;
238 if (i == numPoints - 1)
240 /* Fill the table with the force, minus the derivative of the spline */
245 /* tab[i] will contain the average of the splines over the two intervals */
246 table_f[i] += -0.5 * dc;
251 /* Make spline s(x) = a0 + a1*(x - xr) + 0.5*a2*(x - xr)^2
252 * matching the potential at the two end points
253 * and the derivative dc at the end point xr.
257 a2dx = (a1 * dx + v_r1 - a0) * 2 / dx;
259 /* Set dc to the derivative at the next point */
262 if (dc_new != dc_new || dc_new < -tab_max || dc_new > tab_max)
272 table_f[(i - 1)] = -0.5 * dc;
274 /* Currently the last value only contains half the force: double it */
277 if (!table_fdv0.empty())
279 /* Copy to FDV0 table too. Allocation occurs in forcerec.c,
280 * init_ewald_f_table().
282 for (i = 0; i < numPoints - 1; i++)
284 table_fdv0[4 * i] = table_f[i];
285 table_fdv0[4 * i + 1] = table_f[i + 1] - table_f[i];
286 table_fdv0[4 * i + 2] = table_v[i];
287 table_fdv0[4 * i + 3] = 0.0;
289 const int lastPoint = numPoints - 1;
290 table_fdv0[4 * lastPoint] = table_f[lastPoint];
291 table_fdv0[4 * lastPoint + 1] = -table_f[lastPoint];
292 table_fdv0[4 * lastPoint + 2] = table_v[lastPoint];
293 table_fdv0[4 * lastPoint + 3] = 0.0;
299 /* Returns the spacing for a function using the maximum of
300 * the third derivative, x_scale (unit 1/length)
301 * and function tolerance.
303 static double spline3_table_scale(double third_deriv_max, double x_scale, double func_tol)
306 double sc_deriv, sc_func;
308 /* Force tolerance: single precision accuracy */
309 deriv_tol = GMX_FLOAT_EPS;
310 sc_deriv = sqrt(third_deriv_max / (6 * 4 * deriv_tol * x_scale)) * x_scale;
312 /* Don't try to be more accurate on energy than the precision */
313 func_tol = std::max(func_tol, static_cast<double>(GMX_REAL_EPS));
314 sc_func = std::cbrt(third_deriv_max / (6 * 12 * std::sqrt(3.0) * func_tol)) * x_scale;
316 return std::max(sc_deriv, sc_func);
319 /* The scale (1/spacing) for third order spline interpolation
320 * of the Ewald mesh contribution which needs to be subtracted
321 * from the non-bonded interactions.
322 * Since there is currently only one spacing for Coulomb and LJ,
323 * the finest spacing is used if both Ewald types are present.
325 * Note that we could also implement completely separate tables
326 * for Coulomb and LJ Ewald, each with their own spacing.
327 * The current setup with the same spacing can provide slightly
328 * faster kernels with both Coulomb and LJ Ewald, especially
329 * when interleaving both tables (currently not implemented).
331 real ewald_spline3_table_scale(const interaction_const_t& ic,
332 const bool generateCoulombTables,
333 const bool generateVdwTables)
335 GMX_RELEASE_ASSERT(!generateCoulombTables || EEL_PME_EWALD(ic.eeltype),
336 "Can only use tables with Ewald");
337 GMX_RELEASE_ASSERT(!generateVdwTables || EVDW_PME(ic.vdwtype), "Can only use tables with Ewald");
341 if (generateCoulombTables)
343 GMX_RELEASE_ASSERT(ic.ewaldcoeff_q > 0, "The Ewald coefficient shoule be positive");
345 double erf_x_d3 = 1.0522; /* max of (erf(x)/x)''' */
349 /* Energy tolerance: 0.1 times the cut-off jump */
350 etol = 0.1 * std::erfc(ic.ewaldcoeff_q * ic.rcoulomb);
352 sc_q = spline3_table_scale(erf_x_d3, ic.ewaldcoeff_q, etol);
356 fprintf(debug, "Ewald Coulomb quadratic spline table spacing: %f nm\n", 1 / sc_q);
359 sc = std::max(sc, sc_q);
362 if (generateVdwTables)
364 GMX_RELEASE_ASSERT(ic.ewaldcoeff_lj > 0, "The Ewald coefficient shoule be positive");
366 double func_d3 = 0.42888; /* max of (x^-6 (1 - exp(-x^2)(1+x^2+x^4/2)))''' */
370 /* Energy tolerance: 0.1 times the cut-off jump */
371 xrc2 = gmx::square(ic.ewaldcoeff_lj * ic.rvdw);
372 etol = 0.1 * std::exp(-xrc2) * (1 + xrc2 + xrc2 * xrc2 / 2.0);
374 sc_lj = spline3_table_scale(func_d3, ic.ewaldcoeff_lj, etol);
378 fprintf(debug, "Ewald LJ quadratic spline table spacing: %f nm\n", 1 / sc_lj);
381 sc = std::max(sc, sc_lj);
387 static void copy2table(int n,
390 gmx::ArrayRef<const double> x,
391 gmx::ArrayRef<const double> Vtab,
392 gmx::ArrayRef<const double> Ftab,
394 gmx::ArrayRef<real> dest)
396 /* Use double prec. for the intermediary variables
397 * and temporary x/vtab/vtab2 data to avoid unnecessary
404 for (i = 0; (i < n); i++)
410 G = 3 * (Vtab[i + 1] - Vtab[i]) + (Ftab[i + 1] + 2 * Ftab[i]) * h;
411 H = -2 * (Vtab[i + 1] - Vtab[i]) - (Ftab[i + 1] + Ftab[i]) * h;
415 /* Fill the last entry with a linear potential,
416 * this is mainly for rounding issues with angle and dihedral potentials.
422 nn0 = offset + i * stride;
423 dest[nn0] = scalefactor * Vtab[i];
424 dest[nn0 + 1] = scalefactor * F;
425 dest[nn0 + 2] = scalefactor * G;
426 dest[nn0 + 3] = scalefactor * H;
430 t_tabledata::t_tabledata(int n, int firstTableNum, double scale, bool bAlloc) :
431 nx(n), nx0(firstTableNum), tabscale(scale)
441 static void spline_forces(int nx, double h, const double v[], gmx_bool bS3, gmx_bool bE3, double f[])
444 double v3, b_s, b_e, b;
447 /* Formulas can be found in:
448 * H.J.C. Berendsen, Simulating the Physical World, Cambridge 2007
451 if (nx < 4 && (bS3 || bE3))
454 "Can not generate splines with third derivative boundary conditions with less "
455 "than 4 (%d) points",
459 /* To make life easy we initially set the spacing to 1
460 * and correct for this at the end.
464 /* Fit V''' at the start */
465 v3 = v[3] - 3 * v[2] + 3 * v[1] - v[0];
468 fprintf(debug, "The left third derivative is %g\n", v3 / (h * h * h));
470 b_s = 2 * (v[1] - v[0]) + v3 / 6;
475 /* Fit V'' at the start */
478 v2 = -v[3] + 4 * v[2] - 5 * v[1] + 2 * v[0];
479 /* v2 = v[2] - 2*v[1] + v[0]; */
482 fprintf(debug, "The left second derivative is %g\n", v2 / (h * h));
484 b_s = 3 * (v[1] - v[0]) - v2 / 2;
490 b_s = 3 * (v[2] - v[0]) + f[0] * h;
495 /* Fit V''' at the end */
496 v3 = v[nx - 1] - 3 * v[nx - 2] + 3 * v[nx - 3] - v[nx - 4];
499 fprintf(debug, "The right third derivative is %g\n", v3 / (h * h * h));
501 b_e = 2 * (v[nx - 1] - v[nx - 2]) + v3 / 6;
506 /* V'=0 at the end */
507 b_e = 3 * (v[nx - 1] - v[nx - 3]) + f[nx - 1] * h;
511 std::vector<double> gamma(nx);
512 beta = (bS3 ? 1 : 4);
514 /* For V'' fitting */
515 /* beta = (bS3 ? 2 : 4); */
517 f[start] = b_s / beta;
518 for (i = start + 1; i < end; i++)
522 b = 3 * (v[i + 1] - v[i - 1]);
523 f[i] = (b - f[i - 1]) / beta;
525 gamma[end - 1] = 1 / beta;
526 beta = (bE3 ? 1 : 4) - gamma[end - 1];
527 f[end - 1] = (b_e - f[end - 2]) / beta;
529 for (i = end - 2; i >= start; i--)
531 f[i] -= gamma[i + 1] * f[i + 1];
534 /* Correct for the minus sign and the spacing */
535 for (i = start; i < end; i++)
541 static void set_forces(FILE* fp, int angle, int nx, double h, double v[], double f[], int table)
547 gmx_fatal(FARGS, "Force generation for dihedral tables is not (yet) implemented");
551 while (v[start] == 0)
557 while (v[end - 1] == 0)
573 "Generating forces for table %d, boundary conditions: V''' at %g, %s at %g\n",
576 end == nx ? "V'''" : "V'=0",
579 spline_forces(end - start, h, v + start, TRUE, end == nx, f + start);
582 static std::vector<t_tabledata> read_tables(FILE* fp, const char* filename, int ntab, int angle)
585 double start, end, dx0, dx1, ssd, vm, vp, f, numf;
586 int k, i, nx0 = 0, nny, ns;
587 gmx_bool bAllZero, bZeroV, bZeroF;
591 std::string libfn = gmx::findLibraryFile(filename);
592 gmx::MultiDimArray<std::vector<double>, gmx::dynamicExtents2D> xvgData = readXvgData(libfn);
593 int numColumns = xvgData.extent(0);
594 if (numColumns != nny)
596 gmx_fatal(FARGS, "Trying to read file %s, but nr columns = %d, should be %d", libfn.c_str(), numColumns, nny);
598 int numRows = xvgData.extent(1);
600 const auto& yy = xvgData.asView();
606 "The first distance in file %s is %f nm instead of %f nm",
623 if (yy[0][0] != start || yy[0][numRows - 1] != end)
626 "The angles in file %s should go from %f to %f instead of %f to %f\n",
635 tabscale = (numRows - 1) / (yy[0][numRows - 1] - yy[0][0]);
639 fprintf(fp, "Read user tables from %s with %d data points.\n", libfn.c_str(), numRows);
642 fprintf(fp, "Tabscale = %g points/nm\n", tabscale);
647 for (k = 0; k < ntab; k++)
651 for (i = 0; (i < numRows); i++)
655 dx0 = yy[0][i - 1] - yy[0][i - 2];
656 dx1 = yy[0][i] - yy[0][i - 1];
657 /* Check for 1% deviation in spacing */
658 if (fabs(dx1 - dx0) >= 0.005 * (fabs(dx0) + fabs(dx1)))
661 "In table file '%s' the x values are not equally spaced: %f %f %f",
668 if (yy[1 + k * 2][i] != 0)
676 if (yy[1 + k * 2][i] > 0.01 * GMX_REAL_MAX || yy[1 + k * 2][i] < -0.01 * GMX_REAL_MAX)
678 gmx_fatal(FARGS, "Out of range potential value %g in file '%s'", yy[1 + k * 2][i], filename);
681 if (yy[1 + k * 2 + 1][i] != 0)
689 if (yy[1 + k * 2 + 1][i] > 0.01 * GMX_REAL_MAX || yy[1 + k * 2 + 1][i] < -0.01 * GMX_REAL_MAX)
691 gmx_fatal(FARGS, "Out of range force value %g in file '%s'", yy[1 + k * 2 + 1][i], filename);
696 if (!bZeroV && bZeroF)
698 set_forces(fp, angle, numRows, 1 / tabscale, yy[1 + k * 2].data(), yy[1 + k * 2 + 1].data(), k);
702 /* Check if the second column is close to minus the numerical
703 * derivative of the first column.
707 for (i = 1; (i < numRows - 1); i++)
709 vm = yy[1 + 2 * k][i - 1];
710 vp = yy[1 + 2 * k][i + 1];
711 f = yy[1 + 2 * k + 1][i];
712 if (vm != 0 && vp != 0 && f != 0)
714 /* Take the centered difference */
715 numf = -(vp - vm) * 0.5 * tabscale;
718 ssd += fabs(2 * (f - numf) / (f + numf));
727 "For the %d non-zero entries for table %d in %s the forces deviate on "
729 "%% from minus the numerical derivative of the potential\n",
733 gmx::roundToInt64(100 * ssd));
736 fprintf(debug, "%s", buf);
742 fprintf(fp, "\nWARNING: %s\n", buf);
744 fprintf(stderr, "\nWARNING: %s\n", buf);
751 fprintf(fp, "\nNOTE: All elements in table %s are zero\n\n", libfn.c_str());
754 std::vector<t_tabledata> td;
755 for (k = 0; (k < ntab); k++)
757 td.emplace_back(numRows, nx0, tabscale, true);
758 for (i = 0; (i < numRows); i++)
760 td[k].x[i] = yy[0][i];
761 td[k].v[i] = yy[2 * k + 1][i];
762 td[k].f[i] = yy[2 * k + 2][i];
768 static void fill_table(t_tabledata* td, int tp, const interaction_const_t* ic, gmx_bool b14only)
770 /* Fill the table according to the formulas in the manual.
771 * In principle, we only need the potential and the second
772 * derivative, but then we would have to do lots of calculations
773 * in the inner loop. By precalculating some terms (see manual)
774 * we get better eventual performance, despite a larger table.
776 * Since some of these higher-order terms are very small,
777 * we always use double precision to calculate them here, in order
778 * to avoid unnecessary loss of precision.
782 double r1, rc, r12, r13;
783 double r, r2, r6, rc2;
784 double expr, Vtab, Ftab;
785 /* Parameters for David's function */
786 double A = 0, B = 0, C = 0, A_3 = 0, B_4 = 0;
787 /* Parameters for the switching function */
788 double ksw, swi, swi1;
789 /* Temporary parameters */
790 gmx_bool bPotentialSwitch, bForceSwitch, bPotentialShift;
791 double ewc = ic->ewaldcoeff_q;
792 double ewclj = ic->ewaldcoeff_lj;
797 bPotentialSwitch = FALSE;
798 bForceSwitch = FALSE;
799 bPotentialShift = FALSE;
804 ((tp == etabLJ6Switch) || (tp == etabLJ12Switch) || (tp == etabCOULSwitch)
805 || (tp == etabEwaldSwitch) || (tp == etabEwaldUserSwitch)
806 || (tprops[tp].bCoulomb && (ic->coulomb_modifier == InteractionModifiers::PotSwitch))
807 || (!tprops[tp].bCoulomb && (ic->vdw_modifier == InteractionModifiers::PotSwitch)));
809 ((tp == etabLJ6Shift) || (tp == etabLJ12Shift) || (tp == etabShift)
810 || (tprops[tp].bCoulomb && (ic->coulomb_modifier == InteractionModifiers::ForceSwitch))
811 || (!tprops[tp].bCoulomb && (ic->vdw_modifier == InteractionModifiers::ForceSwitch)));
813 ((tprops[tp].bCoulomb && (ic->coulomb_modifier == InteractionModifiers::PotShift))
814 || (!tprops[tp].bCoulomb && (ic->vdw_modifier == InteractionModifiers::PotShift)));
819 if (tprops[tp].bCoulomb)
821 r1 = ic->rcoulomb_switch;
826 r1 = ic->rvdw_switch;
829 if (bPotentialSwitch)
831 ksw = 1.0 / (gmx::power5(rc - r1));
843 else if (tp == etabLJ6Shift)
852 A = p * ((p + 1) * r1 - (p + 4) * rc) / (std::pow(rc, p + 2) * gmx::square(rc - r1));
853 B = -p * ((p + 1) * r1 - (p + 3) * rc) / (std::pow(rc, p + 2) * gmx::power3(rc - r1));
854 C = 1.0 / std::pow(rc, p) - A / 3.0 * gmx::power3(rc - r1) - B / 4.0 * gmx::power4(rc - r1);
855 if (tp == etabLJ6Shift)
866 fprintf(debug, "Setting up tables\n");
873 double rc6 = 1.0 / (rc2 * rc2 * rc2);
875 if (gmx_within_tol(reppow, 12.0, 10 * GMX_DOUBLE_EPS))
881 rc12 = std::pow(rc, -reppow);
891 Vcut = -rc6 * exp(-ewclj * ewclj * rc2)
892 * (1 + ewclj * ewclj * rc2 + gmx::power4(ewclj) * rc2 * rc2 / 2);
898 case etabCOUL: Vcut = 1.0 / rc; break;
900 case etabEwaldSwitch: Vcut = std::erfc(ewc * rc) / rc; break;
902 /* Only calculate minus the reciprocal space contribution */
903 Vcut = -std::erf(ewc * rc) / rc;
907 /* No need for preventing the usage of modifiers with RF */
910 case etabEXPMIN: Vcut = exp(-rc); break;
913 "Cannot apply new potential-shift modifier to interaction type '%s' yet. "
921 for (i = 0; (i < td->nx); i++)
923 td->x[i] = i / td->tabscale;
925 for (i = td->nx0; (i < td->nx); i++)
929 r6 = 1.0 / (r2 * r2 * r2);
930 if (gmx_within_tol(reppow, 12.0, 10 * GMX_DOUBLE_EPS))
936 r12 = std::pow(r, -reppow);
940 if (bPotentialSwitch)
942 /* swi is function, swi1 1st derivative and swi2 2nd derivative */
943 /* The switch function is 1 for r<r1, 0 for r>rc, and smooth for
944 * r1<=r<=rc. The 1st and 2nd derivatives are both zero at
946 * ksw is just the constant 1/(rc-r1)^5, to save some calculations...
960 swi = 1 - 10 * gmx::power3(r - r1) * ksw * gmx::square(rc - r1)
961 + 15 * gmx::power4(r - r1) * ksw * (rc - r1) - 6 * gmx::power5(r - r1) * ksw;
962 swi1 = -30 * gmx::square(r - r1) * ksw * gmx::square(rc - r1)
963 + 60 * gmx::power3(r - r1) * ksw * (rc - r1) - 30 * gmx::power4(r - r1) * ksw;
966 else /* not really needed, but avoids compiler warnings... */
977 Ftab = 6.0 * Vtab / r;
985 Ftab = 6.0 * Vtab / r;
992 Ftab = reppow * Vtab / r;
1000 Ftab = reppow * Vtab / r;
1007 case etabCOULSwitch:
1016 case etabEwaldSwitch:
1017 Vtab = std::erfc(ewc * r) / r;
1018 Ftab = std::erfc(ewc * r) / r2 + exp(-(ewc * ewc * r2)) * ewc * M_2_SQRTPI / r;
1021 case etabEwaldUserSwitch:
1022 /* Only calculate the negative of the reciprocal space contribution */
1023 Vtab = -std::erf(ewc * r) / r;
1024 Ftab = -std::erf(ewc * r) / r2 + exp(-(ewc * ewc * r2)) * ewc * M_2_SQRTPI / r;
1027 Vtab = -r6 * exp(-ewclj * ewclj * r2)
1028 * (1 + ewclj * ewclj * r2 + gmx::power4(ewclj) * r2 * r2 / 2);
1029 Ftab = 6.0 * Vtab / r
1030 - r6 * exp(-ewclj * ewclj * r2) * gmx::power5(ewclj) * ewclj * r2 * r2 * r;
1034 Vtab = 1.0 / r + ic->reactionFieldCoefficient * r2 - ic->reactionFieldShift;
1035 Ftab = 1.0 / r2 - 2 * ic->reactionFieldCoefficient * r;
1036 if (tp == etabRF_ZERO && r >= rc)
1048 gmx_fatal(FARGS, "Table type %d not implemented yet. (%s,%d)", tp, __FILE__, __LINE__);
1052 /* Normal coulomb with cut-off correction for potential */
1056 /* If in Shifting range add something to it */
1059 r12 = (r - r1) * (r - r1);
1060 r13 = (r - r1) * r12;
1061 Vtab += -A_3 * r13 - B_4 * r12 * r12;
1062 Ftab += A * r12 + B * r13;
1067 /* Make sure interactions are zero outside cutoff with modifiers */
1072 if (bPotentialShift)
1080 /* Make sure interactions are zero outside cutoff with modifiers */
1092 if (bPotentialSwitch)
1096 /* Make sure interactions are zero outside cutoff with modifiers */
1102 Ftab = Ftab * swi - Vtab * swi1;
1106 /* Convert to single precision when we store to mem */
1111 /* Continue the table linearly from nx0 to 0.
1112 * These values are only required for energy minimization with overlap or TPI.
1114 for (i = td->nx0 - 1; i >= 0; i--)
1116 td->v[i] = td->v[i + 1] + td->f[i + 1] * (td->x[i + 1] - td->x[i]);
1117 td->f[i] = td->f[i + 1];
1121 static void set_table_type(int tabsel[], const interaction_const_t* ic, gmx_bool b14only)
1123 /* Set the different table indices.
1127 CoulombInteractionType eltype;
1128 VanDerWaalsType vdwtype;
1132 switch (ic->eeltype)
1134 case CoulombInteractionType::User:
1135 case CoulombInteractionType::PmeUser:
1136 case CoulombInteractionType::PmeUserSwitch:
1137 eltype = CoulombInteractionType::User;
1139 default: eltype = CoulombInteractionType::Cut;
1144 eltype = ic->eeltype;
1149 case CoulombInteractionType::Cut: tabsel[etiCOUL] = etabCOUL; break;
1150 case CoulombInteractionType::Poisson: tabsel[etiCOUL] = etabShift; break;
1151 case CoulombInteractionType::Shift:
1152 if (ic->rcoulomb > ic->rcoulomb_switch)
1154 tabsel[etiCOUL] = etabShift;
1158 tabsel[etiCOUL] = etabCOUL;
1161 case CoulombInteractionType::Ewald:
1162 case CoulombInteractionType::Pme:
1163 case CoulombInteractionType::P3mAD: tabsel[etiCOUL] = etabEwald; break;
1164 case CoulombInteractionType::PmeSwitch: tabsel[etiCOUL] = etabEwaldSwitch; break;
1165 case CoulombInteractionType::PmeUser: tabsel[etiCOUL] = etabEwaldUser; break;
1166 case CoulombInteractionType::PmeUserSwitch: tabsel[etiCOUL] = etabEwaldUserSwitch; break;
1167 case CoulombInteractionType::RF:
1168 case CoulombInteractionType::RFZero: tabsel[etiCOUL] = etabRF_ZERO; break;
1169 case CoulombInteractionType::Switch: tabsel[etiCOUL] = etabCOULSwitch; break;
1170 case CoulombInteractionType::User: tabsel[etiCOUL] = etabUSER; break;
1171 default: gmx_fatal(FARGS, "Invalid eeltype %s", enumValueToString(eltype));
1174 /* Van der Waals time */
1175 if (ic->useBuckingham && !b14only)
1177 tabsel[etiLJ6] = etabLJ6;
1178 tabsel[etiLJ12] = etabEXPMIN;
1182 if (b14only && ic->vdwtype != VanDerWaalsType::User)
1184 vdwtype = VanDerWaalsType::Cut;
1188 vdwtype = ic->vdwtype;
1193 case VanDerWaalsType::Switch:
1194 tabsel[etiLJ6] = etabLJ6Switch;
1195 tabsel[etiLJ12] = etabLJ12Switch;
1197 case VanDerWaalsType::Shift:
1198 tabsel[etiLJ6] = etabLJ6Shift;
1199 tabsel[etiLJ12] = etabLJ12Shift;
1201 case VanDerWaalsType::User:
1202 tabsel[etiLJ6] = etabUSER;
1203 tabsel[etiLJ12] = etabUSER;
1205 case VanDerWaalsType::Cut:
1206 tabsel[etiLJ6] = etabLJ6;
1207 tabsel[etiLJ12] = etabLJ12;
1209 case VanDerWaalsType::Pme:
1210 tabsel[etiLJ6] = etabLJ6Ewald;
1211 tabsel[etiLJ12] = etabLJ12;
1214 gmx_fatal(FARGS, "Invalid vdwtype %s in %s line %d", enumValueToString(vdwtype), __FILE__, __LINE__);
1217 if (!b14only && ic->vdw_modifier != InteractionModifiers::None)
1219 if (ic->vdw_modifier != InteractionModifiers::PotShift && ic->vdwtype != VanDerWaalsType::Cut)
1222 "Potential modifiers other than potential-shift are only implemented for "
1226 /* LJ-PME and other (shift-only) modifiers are handled by applying the modifiers
1227 * to the original interaction forms when we fill the table, so we only check cutoffs here.
1229 if (ic->vdwtype == VanDerWaalsType::Cut)
1231 switch (ic->vdw_modifier)
1233 case InteractionModifiers::None:
1234 case InteractionModifiers::PotShift:
1235 case InteractionModifiers::ExactCutoff:
1236 /* No modification */
1238 case InteractionModifiers::PotSwitch:
1239 tabsel[etiLJ6] = etabLJ6Switch;
1240 tabsel[etiLJ12] = etabLJ12Switch;
1242 case InteractionModifiers::ForceSwitch:
1243 tabsel[etiLJ6] = etabLJ6Shift;
1244 tabsel[etiLJ12] = etabLJ12Shift;
1246 default: gmx_incons("Unsupported vdw_modifier");
1253 std::unique_ptr<t_forcetable>
1254 make_tables(FILE* fp, const interaction_const_t* ic, const char* fn, real rtab, int flags)
1256 gmx_bool b14only, useUserTable;
1257 int nx0, tabsel[etiNR];
1260 auto table = std::make_unique<t_forcetable>(
1261 TableInteraction::ElectrostaticVdwRepulsionVdwDispersion, TableFormat::CubicsplineYfgh);
1263 b14only = ((flags & GMX_MAKETABLES_14ONLY) != 0);
1265 if (flags & GMX_MAKETABLES_FORCEUSER)
1267 tabsel[etiCOUL] = etabUSER;
1268 tabsel[etiLJ6] = etabUSER;
1269 tabsel[etiLJ12] = etabUSER;
1273 set_table_type(tabsel, ic, b14only);
1275 std::vector<t_tabledata> td;
1276 table->interactionRange = rtab;
1278 table->numTablePoints = 0;
1280 table->numInteractions = etiNR;
1281 table->stride = table->formatsize * table->numInteractions;
1283 /* Check whether we have to read or generate */
1284 useUserTable = FALSE;
1285 for (unsigned int i = 0; (i < etiNR); i++)
1287 if (ETAB_USER(tabsel[i]))
1289 useUserTable = TRUE;
1294 td = read_tables(fp, fn, etiNR, 0);
1295 if (rtab == 0 || (flags & GMX_MAKETABLES_14ONLY))
1297 table->numTablePoints = td[0].nx;
1301 if (td[0].x[td[0].nx - 1] < rtab)
1304 "Tables in file %s not long enough for cut-off:\n"
1305 "\tshould be at least %f nm\n",
1309 table->numTablePoints = gmx::roundToInt(rtab * td[0].tabscale);
1311 table->scale = td[0].tabscale;
1317 // No tables are read
1319 table->scale = 2000.0;
1321 table->scale = 500.0;
1323 table->numTablePoints = static_cast<int>(rtab * table->scale);
1327 /* Each table type (e.g. coul,lj6,lj12) requires four
1328 * numbers per table->numTablePoints+1 data points. For performance reasons we want
1329 * the table data to be aligned to (at least) a 32-byte boundary.
1331 table->data.resize(table->stride * (table->numTablePoints + 1) * sizeof(real));
1333 for (int k = 0; (k < etiNR); k++)
1335 /* Now fill data for tables that have not been read
1336 * or add the Ewald long-range correction for Ewald user tables.
1338 if (tabsel[k] != etabUSER)
1340 real scale = table->scale;
1341 if (ic->useBuckingham && (ic->buckinghamBMax != 0) && tabsel[k] == etabEXPMIN)
1343 scale /= ic->buckinghamBMax;
1345 td[k] = t_tabledata(table->numTablePoints, nx0, scale, !useUserTable);
1347 fill_table(&(td[k]), tabsel[k], ic, b14only);
1351 "Generated table with %d data points for %s%s.\n"
1352 "Tabscale = %g points/nm\n",
1354 b14only ? "1-4 " : "",
1355 tprops[tabsel[k]].name,
1360 /* Set scalefactor for c6/c12 tables. This is because we save flops in the non-table kernels
1361 * by including the derivative constants (6.0 or 12.0) in the parameters, since
1362 * we no longer calculate force in most steps. This means the c6/c12 parameters
1363 * have been scaled up, so we need to scale down the table interactions too.
1364 * It comes here since we need to scale user tables too.
1368 scalefactor = 1.0 / 6.0;
1370 else if (k == etiLJ12 && tabsel[k] != etabEXPMIN)
1372 scalefactor = 1.0 / 12.0;
1379 copy2table(table->numTablePoints,
1380 k * table->formatsize,
1392 bondedtable_t make_bonded_table(FILE* fplog, const char* fn, int angle)
1398 t_tabledata td = read_tables(fplog, fn, 1, angle)[0];
1401 /* Convert the table from degrees to radians */
1402 for (i = 0; i < td.nx; i++)
1404 td.x[i] *= gmx::c_deg2Rad;
1405 td.f[i] *= gmx::c_rad2Deg;
1407 td.tabscale *= gmx::c_rad2Deg;
1410 tab.scale = td.tabscale;
1411 tab.data.resize(tab.n * stride);
1412 copy2table(tab.n, 0, stride, td.x, td.v, td.f, 1.0, tab.data);
1417 std::unique_ptr<t_forcetable>
1418 makeDispersionCorrectionTable(FILE* fp, const interaction_const_t* ic, real rtab, const char* tabfn)
1420 GMX_RELEASE_ASSERT(ic->vdwtype != VanDerWaalsType::User || tabfn,
1421 "With VdW user tables we need a table file name");
1423 std::unique_ptr<t_forcetable> fullTable = make_tables(fp, ic, tabfn, rtab, 0);
1424 /* Copy the contents of the table to one that has just dispersion
1425 * and repulsion, to improve cache performance. We want the table
1426 * data to be aligned to 32-byte boundaries.
1428 std::unique_ptr<t_forcetable> dispersionCorrectionTable = std::make_unique<t_forcetable>(
1429 TableInteraction::VdwRepulsionVdwDispersion, fullTable->format);
1430 dispersionCorrectionTable->interactionRange = fullTable->interactionRange;
1431 dispersionCorrectionTable->numTablePoints = fullTable->numTablePoints;
1432 dispersionCorrectionTable->scale = fullTable->scale;
1433 dispersionCorrectionTable->numInteractions = 2;
1434 dispersionCorrectionTable->stride =
1435 dispersionCorrectionTable->formatsize * dispersionCorrectionTable->numInteractions;
1436 dispersionCorrectionTable->data.resize(dispersionCorrectionTable->stride
1437 * (dispersionCorrectionTable->numTablePoints + 1));
1439 for (int i = 0; i <= fullTable->numTablePoints; i++)
1441 for (int j = 0; j < 8; j++)
1443 dispersionCorrectionTable->data[8 * i + j] = fullTable->data[12 * i + 4 + j];
1447 return dispersionCorrectionTable;
1450 t_forcetable::t_forcetable(enum TableInteraction interaction, enum TableFormat format) :
1451 interaction(interaction),
1453 interactionRange(0),
1461 t_forcetable::~t_forcetable() = default;