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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/mdtypes/inputrec.h"
52 #include "gromacs/pbcutil/pbc.h"
53 #include "gromacs/pbcutil/rmpbc.h"
54 #include "gromacs/topology/index.h"
55 #include "gromacs/topology/topology.h"
56 #include "gromacs/utility/arraysize.h"
57 #include "gromacs/utility/cstringutil.h"
58 #include "gromacs/utility/fatalerror.h"
59 #include "gromacs/utility/smalloc.h"
61 static void calc_com_pbc(int nrefat, const t_topology* top, rvec x[], t_pbc* pbc, const int index[], rvec xref, int ePBC)
63 const real tol = 1e-4;
69 /* First simple calculation */
72 for (m = 0; (m < nrefat); m++)
75 mass = top->atoms.atom[ai].m;
76 for (j = 0; (j < DIM); j++)
78 xref[j] += mass * x[ai][j];
82 svmul(1 / mtot, xref, xref);
83 /* Now check if any atom is more than half the box from the COM */
90 for (m = 0; (m < nrefat); m++)
93 mass = top->atoms.atom[ai].m / mtot;
94 pbc_dx(pbc, x[ai], xref, dx);
95 rvec_add(xref, dx, xtest);
96 for (j = 0; (j < DIM); j++)
98 if (std::abs(xtest[j] - x[ai][j]) > tol)
100 /* Here we have used the wrong image for contributing to the COM */
101 xref[j] += mass * (xtest[j] - x[ai][j]);
109 printf("COM: %8.3f %8.3f %8.3f iter = %d\n", xref[XX], xref[YY], xref[ZZ], iter);
116 static void spol_atom2molindex(int* n, int* index, const t_block* mols)
125 while (m < mols->nr && index[i] != mols->index[m])
131 gmx_fatal(FARGS, "index[%d]=%d does not correspond to the first atom of a molecule",
132 i + 1, index[i] + 1);
134 for (j = mols->index[m]; j < mols->index[m + 1]; j++)
136 if (i >= *n || index[i] != j)
138 gmx_fatal(FARGS, "The index group is not a set of whole molecules");
142 /* Modify the index in place */
145 printf("There are %d molecules in the selection\n", nmol);
150 int gmx_spol(int argc, char* argv[])
155 int nrefat, natoms, nf, ntot;
157 rvec * x, xref, trial, dx = { 0 }, dip, dir;
161 int * isize, nrefgrp;
162 int ** index, *molindex;
164 real rmin2, rmax2, rcut, rcut2, rdx2 = 0, rtry2, qav, q, dip2, invbw;
165 int nbin, i, m, mol, a0, a1, a, d;
166 double sdip, sdip2, sinp, sdinp, nmol;
169 gmx_rmpbc_t gpbc = nullptr;
172 const char* desc[] = {
173 "[THISMODULE] analyzes dipoles around a solute; it is especially useful",
174 "for polarizable water. A group of reference atoms, or a center",
175 "of mass reference (option [TT]-com[tt]) and a group of solvent",
176 "atoms is required. The program splits the group of solvent atoms",
177 "into molecules. For each solvent molecule the distance to the",
178 "closest atom in reference group or to the COM is determined.",
179 "A cumulative distribution of these distances is plotted.",
180 "For each distance between [TT]-rmin[tt] and [TT]-rmax[tt]",
181 "the inner product of the distance vector",
182 "and the dipole of the solvent molecule is determined.",
183 "For solvent molecules with net charge (ions), the net charge of the ion",
184 "is subtracted evenly from all atoms in the selection of each ion.",
185 "The average of these dipole components is printed.",
186 "The same is done for the polarization, where the average dipole is",
187 "subtracted from the instantaneous dipole. The magnitude of the average",
188 "dipole is set with the option [TT]-dip[tt], the direction is defined",
189 "by the vector from the first atom in the selected solvent group",
190 "to the midpoint between the second and the third atom."
193 gmx_output_env_t* oenv;
194 static gmx_bool bCom = FALSE;
195 static int srefat = 1;
196 static real rmin = 0.0, rmax = 0.32, refdip = 0, bw = 0.01;
198 { "-com", FALSE, etBOOL, { &bCom }, "Use the center of mass as the reference position" },
199 { "-refat", FALSE, etINT, { &srefat }, "The reference atom of the solvent molecule" },
200 { "-rmin", FALSE, etREAL, { &rmin }, "Maximum distance (nm)" },
201 { "-rmax", FALSE, etREAL, { &rmax }, "Maximum distance (nm)" },
202 { "-dip", FALSE, etREAL, { &refdip }, "The average dipole (D)" },
203 { "-bw", FALSE, etREAL, { &bw }, "The bin width" }
206 t_filenm fnm[] = { { efTRX, nullptr, nullptr, ffREAD },
207 { efTPR, nullptr, nullptr, ffREAD },
208 { efNDX, nullptr, nullptr, ffOPTRD },
209 { efXVG, nullptr, "scdist", ffWRITE } };
210 #define NFILE asize(fnm)
212 if (!parse_common_args(&argc, argv, PCA_CAN_TIME | PCA_CAN_VIEW, NFILE, fnm, asize(pa), pa,
213 asize(desc), desc, 0, nullptr, &oenv))
219 // TODO: Only ePBC is used, not the full inputrec.
220 t_inputrec irInstance;
221 t_inputrec* ir = &irInstance;
222 read_tpx_top(ftp2fn(efTPR, NFILE, fnm), ir, box, &natoms, nullptr, nullptr, top);
224 /* get index groups */
225 printf("Select a group of reference particles and a solvent group:\n");
229 get_index(&top->atoms, ftp2fn_null(efNDX, NFILE, fnm), 2, isize, index, grpname);
242 spol_atom2molindex(&(isize[1]), index[1], &(top->mols));
245 /* initialize reading trajectory: */
246 natoms = read_first_x(oenv, &status, ftp2fn(efTRX, NFILE, fnm), &t, &x, box);
248 rcut = 0.99 * std::sqrt(max_cutoff2(ir->ePBC, box));
253 rcut2 = gmx::square(rcut);
255 nbin = static_cast<int>(rcut * invbw) + 2;
258 rmin2 = gmx::square(rmin);
259 rmax2 = gmx::square(rmax);
268 molindex = top->mols.index;
269 atom = top->atoms.atom;
271 gpbc = gmx_rmpbc_init(&top->idef, ir->ePBC, natoms);
273 /* start analysis of trajectory */
276 /* make molecules whole again */
277 gmx_rmpbc(gpbc, natoms, box, x);
279 set_pbc(&pbc, ir->ePBC, box);
282 calc_com_pbc(nrefat, top, x, &pbc, index[0], xref, ir->ePBC);
285 for (m = 0; m < isize[1]; m++)
289 a1 = molindex[mol + 1];
290 for (i = 0; i < nrefgrp; i++)
292 pbc_dx(&pbc, x[a0 + srefat], bCom ? xref : x[index[0][i]], trial);
293 rtry2 = norm2(trial);
294 if (i == 0 || rtry2 < rdx2)
296 copy_rvec(trial, dx);
302 hist[static_cast<int>(std::sqrt(rdx2) * invbw) + 1]++;
304 if (rdx2 >= rmin2 && rdx2 < rmax2)
309 for (a = a0; a < a1; a++)
314 for (a = a0; a < a1; a++)
317 for (d = 0; d < DIM; d++)
319 dip[d] += q * x[a][d];
322 for (d = 0; d < DIM; d++)
326 for (a = a0 + 1; a < a0 + 3; a++)
328 for (d = 0; d < DIM; d++)
330 dir[d] += 0.5 * x[a][d];
335 svmul(ENM2DEBYE, dip, dip);
337 sdip += std::sqrt(dip2);
339 for (d = 0; d < DIM; d++)
341 sinp += dx[d] * dip[d];
342 sdinp += dx[d] * (dip[d] - refdip * dir[d]);
350 } while (read_next_x(oenv, status, &t, x, box));
352 gmx_rmpbc_done(gpbc);
358 fprintf(stderr, "Average number of molecules within %g nm is %.1f\n", rmax,
359 static_cast<real>(ntot) / nf);
366 fprintf(stderr, "Average dipole: %f (D), std.dev. %f\n", sdip,
367 std::sqrt(sdip2 - gmx::square(sdip)));
368 fprintf(stderr, "Average radial component of the dipole: %f (D)\n", sinp);
369 fprintf(stderr, "Average radial component of the polarization: %f (D)\n", sdinp);
372 fp = xvgropen(opt2fn("-o", NFILE, fnm), "Cumulative solvent distribution", "r (nm)", "molecules", oenv);
374 for (i = 0; i <= nbin; i++)
377 fprintf(fp, "%g %g\n", i * bw, nmol / nf);
381 do_view(oenv, opt2fn("-o", NFILE, fnm), nullptr);