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41 #include "gromacs/commandline/pargs.h"
42 #include "gromacs/commandline/viewit.h"
43 #include "gromacs/fileio/tpxio.h"
44 #include "gromacs/fileio/trxio.h"
45 #include "gromacs/fileio/xvgr.h"
46 #include "gromacs/gmxana/gmx_ana.h"
47 #include "gromacs/gmxana/gstat.h"
48 #include "gromacs/math/functions.h"
49 #include "gromacs/math/units.h"
50 #include "gromacs/math/vec.h"
51 #include "gromacs/mdrunutility/mdmodules.h"
52 #include "gromacs/mdtypes/inputrec.h"
53 #include "gromacs/pbcutil/pbc.h"
54 #include "gromacs/pbcutil/rmpbc.h"
55 #include "gromacs/topology/index.h"
56 #include "gromacs/topology/topology.h"
57 #include "gromacs/utility/arraysize.h"
58 #include "gromacs/utility/cstringutil.h"
59 #include "gromacs/utility/fatalerror.h"
60 #include "gromacs/utility/smalloc.h"
62 static void calc_com_pbc(int nrefat, const t_topology *top, rvec x[], t_pbc *pbc,
63 int index[], rvec xref, int ePBC)
65 const real tol = 1e-4;
71 /* First simple calculation */
74 for (m = 0; (m < nrefat); m++)
77 mass = top->atoms.atom[ai].m;
78 for (j = 0; (j < DIM); j++)
80 xref[j] += mass*x[ai][j];
84 svmul(1/mtot, xref, xref);
85 /* Now check if any atom is more than half the box from the COM */
92 for (m = 0; (m < nrefat); m++)
95 mass = top->atoms.atom[ai].m/mtot;
96 pbc_dx(pbc, x[ai], xref, dx);
97 rvec_add(xref, dx, xtest);
98 for (j = 0; (j < DIM); j++)
100 if (std::abs(xtest[j]-x[ai][j]) > tol)
102 /* Here we have used the wrong image for contributing to the COM */
103 xref[j] += mass*(xtest[j]-x[ai][j]);
111 printf("COM: %8.3f %8.3f %8.3f iter = %d\n", xref[XX], xref[YY], xref[ZZ], iter);
119 void spol_atom2molindex(int *n, int *index, const t_block *mols)
128 while (m < mols->nr && index[i] != mols->index[m])
134 gmx_fatal(FARGS, "index[%d]=%d does not correspond to the first atom of a molecule", i+1, index[i]+1);
136 for (j = mols->index[m]; j < mols->index[m+1]; j++)
138 if (i >= *n || index[i] != j)
140 gmx_fatal(FARGS, "The index group is not a set of whole molecules");
144 /* Modify the index in place */
147 printf("There are %d molecules in the selection\n", nmol);
152 int gmx_spol(int argc, char *argv[])
158 int nrefat, natoms, nf, ntot;
160 rvec *x, xref, trial, dx = {0}, dip, dir;
165 int **index, *molindex;
167 real rmin2, rmax2, rcut, rcut2, rdx2 = 0, rtry2, qav, q, dip2, invbw;
168 int nbin, i, m, mol, a0, a1, a, d;
169 double sdip, sdip2, sinp, sdinp, nmol;
172 gmx_rmpbc_t gpbc = nullptr;
175 const char *desc[] = {
176 "[THISMODULE] analyzes dipoles around a solute; it is especially useful",
177 "for polarizable water. A group of reference atoms, or a center",
178 "of mass reference (option [TT]-com[tt]) and a group of solvent",
179 "atoms is required. The program splits the group of solvent atoms",
180 "into molecules. For each solvent molecule the distance to the",
181 "closest atom in reference group or to the COM is determined.",
182 "A cumulative distribution of these distances is plotted.",
183 "For each distance between [TT]-rmin[tt] and [TT]-rmax[tt]",
184 "the inner product of the distance vector",
185 "and the dipole of the solvent molecule is determined.",
186 "For solvent molecules with net charge (ions), the net charge of the ion",
187 "is subtracted evenly from all atoms in the selection of each ion.",
188 "The average of these dipole components is printed.",
189 "The same is done for the polarization, where the average dipole is",
190 "subtracted from the instantaneous dipole. The magnitude of the average",
191 "dipole is set with the option [TT]-dip[tt], the direction is defined",
192 "by the vector from the first atom in the selected solvent group",
193 "to the midpoint between the second and the third atom."
196 gmx_output_env_t *oenv;
197 static gmx_bool bCom = FALSE;
198 static int srefat = 1;
199 static real rmin = 0.0, rmax = 0.32, refdip = 0, bw = 0.01;
201 { "-com", FALSE, etBOOL, {&bCom},
202 "Use the center of mass as the reference position" },
203 { "-refat", FALSE, etINT, {&srefat},
204 "The reference atom of the solvent molecule" },
205 { "-rmin", FALSE, etREAL, {&rmin}, "Maximum distance (nm)" },
206 { "-rmax", FALSE, etREAL, {&rmax}, "Maximum distance (nm)" },
207 { "-dip", FALSE, etREAL, {&refdip}, "The average dipole (D)" },
208 { "-bw", FALSE, etREAL, {&bw}, "The bin width" }
212 { efTRX, nullptr, nullptr, ffREAD },
213 { efTPR, nullptr, nullptr, ffREAD },
214 { efNDX, nullptr, nullptr, ffOPTRD },
215 { efXVG, nullptr, "scdist", ffWRITE }
217 #define NFILE asize(fnm)
219 if (!parse_common_args(&argc, argv, PCA_CAN_TIME | PCA_CAN_VIEW,
220 NFILE, fnm, asize(pa), pa, asize(desc), desc, 0, nullptr, &oenv))
226 // TODO: Only ePBC is used, not the full inputrec.
227 gmx::MDModules mdModules;
228 ir = mdModules.inputrec();
229 read_tpx_top(ftp2fn(efTPR, NFILE, fnm),
230 ir, box, &natoms, nullptr, nullptr, top);
232 /* get index groups */
233 printf("Select a group of reference particles and a solvent group:\n");
237 get_index(&top->atoms, ftp2fn_null(efNDX, NFILE, fnm), 2, isize, index, grpname);
250 spol_atom2molindex(&(isize[1]), index[1], &(top->mols));
253 /* initialize reading trajectory: */
254 natoms = read_first_x(oenv, &status, ftp2fn(efTRX, NFILE, fnm), &t, &x, box);
256 rcut = 0.99*std::sqrt(max_cutoff2(ir->ePBC, box));
261 rcut2 = gmx::square(rcut);
263 nbin = static_cast<int>(rcut*invbw)+2;
266 rmin2 = gmx::square(rmin);
267 rmax2 = gmx::square(rmax);
276 molindex = top->mols.index;
277 atom = top->atoms.atom;
279 gpbc = gmx_rmpbc_init(&top->idef, ir->ePBC, natoms);
281 /* start analysis of trajectory */
284 /* make molecules whole again */
285 gmx_rmpbc(gpbc, natoms, box, x);
287 set_pbc(&pbc, ir->ePBC, box);
290 calc_com_pbc(nrefat, top, x, &pbc, index[0], xref, ir->ePBC);
293 for (m = 0; m < isize[1]; m++)
297 a1 = molindex[mol+1];
298 for (i = 0; i < nrefgrp; i++)
300 pbc_dx(&pbc, x[a0+srefat], bCom ? xref : x[index[0][i]], trial);
301 rtry2 = norm2(trial);
302 if (i == 0 || rtry2 < rdx2)
304 copy_rvec(trial, dx);
310 hist[static_cast<int>(std::sqrt(rdx2)*invbw)+1]++;
312 if (rdx2 >= rmin2 && rdx2 < rmax2)
317 for (a = a0; a < a1; a++)
322 for (a = a0; a < a1; a++)
325 for (d = 0; d < DIM; d++)
330 for (d = 0; d < DIM; d++)
334 for (a = a0+1; a < a0+3; a++)
336 for (d = 0; d < DIM; d++)
338 dir[d] += 0.5*x[a][d];
343 svmul(ENM2DEBYE, dip, dip);
345 sdip += std::sqrt(dip2);
347 for (d = 0; d < DIM; d++)
349 sinp += dx[d]*dip[d];
350 sdinp += dx[d]*(dip[d] - refdip*dir[d]);
359 while (read_next_x(oenv, status, &t, x, box));
361 gmx_rmpbc_done(gpbc);
367 fprintf(stderr, "Average number of molecules within %g nm is %.1f\n",
368 rmax, static_cast<real>(ntot)/nf);
375 fprintf(stderr, "Average dipole: %f (D), std.dev. %f\n",
376 sdip, std::sqrt(sdip2-gmx::square(sdip)));
377 fprintf(stderr, "Average radial component of the dipole: %f (D)\n",
379 fprintf(stderr, "Average radial component of the polarization: %f (D)\n",
383 fp = xvgropen(opt2fn("-o", NFILE, fnm),
384 "Cumulative solvent distribution", "r (nm)", "molecules", oenv);
386 for (i = 0; i <= nbin; i++)
389 fprintf(fp, "%g %g\n", i*bw, nmol/nf);
393 do_view(oenv, opt2fn("-o", NFILE, fnm), nullptr);