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41 #include "gromacs/commandline/pargs.h"
42 #include "gromacs/fileio/tpxio.h"
43 #include "gromacs/fileio/trxio.h"
44 #include "gromacs/fileio/xvgr.h"
45 #include "gromacs/gmxana/gmx_ana.h"
46 #include "gromacs/gmxana/gstat.h"
47 #include "gromacs/legacyheaders/macros.h"
48 #include "gromacs/legacyheaders/viewit.h"
49 #include "gromacs/math/units.h"
50 #include "gromacs/math/vec.h"
51 #include "gromacs/pbcutil/pbc.h"
52 #include "gromacs/pbcutil/rmpbc.h"
53 #include "gromacs/topology/index.h"
54 #include "gromacs/utility/cstringutil.h"
55 #include "gromacs/utility/fatalerror.h"
56 #include "gromacs/utility/smalloc.h"
58 static void calc_com_pbc(int nrefat, t_topology *top, rvec x[], t_pbc *pbc,
59 atom_id index[], rvec xref, int ePBC)
61 const real tol = 1e-4;
67 /* First simple calculation */
70 for (m = 0; (m < nrefat); m++)
73 mass = top->atoms.atom[ai].m;
74 for (j = 0; (j < DIM); j++)
76 xref[j] += mass*x[ai][j];
80 svmul(1/mtot, xref, xref);
81 /* Now check if any atom is more than half the box from the COM */
88 for (m = 0; (m < nrefat); m++)
91 mass = top->atoms.atom[ai].m/mtot;
92 pbc_dx(pbc, x[ai], xref, dx);
93 rvec_add(xref, dx, xtest);
94 for (j = 0; (j < DIM); j++)
96 if (std::abs(xtest[j]-x[ai][j]) > tol)
98 /* Here we have used the wrong image for contributing to the COM */
99 xref[j] += mass*(xtest[j]-x[ai][j]);
107 printf("COM: %8.3f %8.3f %8.3f iter = %d\n", xref[XX], xref[YY], xref[ZZ], iter);
115 void spol_atom2molindex(int *n, int *index, t_block *mols)
124 while (m < mols->nr && index[i] != mols->index[m])
130 gmx_fatal(FARGS, "index[%d]=%d does not correspond to the first atom of a molecule", i+1, index[i]+1);
132 for (j = mols->index[m]; j < mols->index[m+1]; j++)
134 if (i >= *n || index[i] != j)
136 gmx_fatal(FARGS, "The index group is not a set of whole molecules");
140 /* Modify the index in place */
143 printf("There are %d molecules in the selection\n", nmol);
148 int gmx_spol(int argc, char *argv[])
154 int nrefat, natoms, nf, ntot;
156 rvec *x, xref, trial, dx = {0}, dip, dir;
161 atom_id **index, *molindex;
163 real rmin2, rmax2, rcut, rcut2, rdx2 = 0, rtry2, qav, q, dip2, invbw;
164 int nbin, i, m, mol, a0, a1, a, d;
165 double sdip, sdip2, sinp, sdinp, nmol;
168 gmx_rmpbc_t gpbc = NULL;
171 const char *desc[] = {
172 "[THISMODULE] analyzes dipoles around a solute; it is especially useful",
173 "for polarizable water. A group of reference atoms, or a center",
174 "of mass reference (option [TT]-com[tt]) and a group of solvent",
175 "atoms is required. The program splits the group of solvent atoms",
176 "into molecules. For each solvent molecule the distance to the",
177 "closest atom in reference group or to the COM is determined.",
178 "A cumulative distribution of these distances is plotted.",
179 "For each distance between [TT]-rmin[tt] and [TT]-rmax[tt]",
180 "the inner product of the distance vector",
181 "and the dipole of the solvent molecule is determined.",
182 "For solvent molecules with net charge (ions), the net charge of the ion",
183 "is subtracted evenly from all atoms in the selection of each ion.",
184 "The average of these dipole components is printed.",
185 "The same is done for the polarization, where the average dipole is",
186 "subtracted from the instantaneous dipole. The magnitude of the average",
187 "dipole is set with the option [TT]-dip[tt], the direction is defined",
188 "by the vector from the first atom in the selected solvent group",
189 "to the midpoint between the second and the third atom."
193 static gmx_bool bCom = FALSE;
194 static int srefat = 1;
195 static real rmin = 0.0, rmax = 0.32, refdip = 0, bw = 0.01;
197 { "-com", FALSE, etBOOL, {&bCom},
198 "Use the center of mass as the reference postion" },
199 { "-refat", FALSE, etINT, {&srefat},
200 "The reference atom of the solvent molecule" },
201 { "-rmin", FALSE, etREAL, {&rmin}, "Maximum distance (nm)" },
202 { "-rmax", FALSE, etREAL, {&rmax}, "Maximum distance (nm)" },
203 { "-dip", FALSE, etREAL, {&refdip}, "The average dipole (D)" },
204 { "-bw", FALSE, etREAL, {&bw}, "The bin width" }
208 { efTRX, NULL, NULL, ffREAD },
209 { efTPR, NULL, NULL, ffREAD },
210 { efNDX, NULL, NULL, ffOPTRD },
211 { efXVG, NULL, "scdist", ffWRITE }
213 #define NFILE asize(fnm)
215 if (!parse_common_args(&argc, argv, PCA_CAN_TIME | PCA_CAN_VIEW,
216 NFILE, fnm, asize(pa), pa, asize(desc), desc, 0, NULL, &oenv))
223 read_tpx_top(ftp2fn(efTPR, NFILE, fnm),
224 ir, box, &natoms, NULL, NULL, NULL, top);
226 /* get index groups */
227 printf("Select a group of reference particles and a solvent group:\n");
231 get_index(&top->atoms, ftp2fn_null(efNDX, NFILE, fnm), 2, isize, index, grpname);
244 spol_atom2molindex(&(isize[1]), index[1], &(top->mols));
247 /* initialize reading trajectory: */
248 natoms = read_first_x(oenv, &status, ftp2fn(efTRX, NFILE, fnm), &t, &x, box);
250 rcut = 0.99*std::sqrt(max_cutoff2(ir->ePBC, box));
257 nbin = static_cast<int>(rcut*invbw)+2;
270 molindex = top->mols.index;
271 atom = top->atoms.atom;
273 gpbc = gmx_rmpbc_init(&top->idef, ir->ePBC, natoms);
275 /* start analysis of trajectory */
278 /* make molecules whole again */
279 gmx_rmpbc(gpbc, natoms, box, x);
281 set_pbc(&pbc, ir->ePBC, box);
284 calc_com_pbc(nrefat, top, x, &pbc, index[0], xref, ir->ePBC);
287 for (m = 0; m < isize[1]; m++)
291 a1 = molindex[mol+1];
292 for (i = 0; i < nrefgrp; i++)
294 pbc_dx(&pbc, x[a0+srefat], bCom ? xref : x[index[0][i]], trial);
295 rtry2 = norm2(trial);
296 if (i == 0 || rtry2 < rdx2)
298 copy_rvec(trial, dx);
304 hist[static_cast<int>(std::sqrt(rdx2)*invbw)+1]++;
306 if (rdx2 >= rmin2 && rdx2 < rmax2)
311 for (a = a0; a < a1; a++)
316 for (a = a0; a < a1; a++)
319 for (d = 0; d < DIM; d++)
324 for (d = 0; d < DIM; d++)
328 for (a = a0+1; a < a0+3; a++)
330 for (d = 0; d < DIM; d++)
332 dir[d] += 0.5*x[a][d];
337 svmul(ENM2DEBYE, dip, dip);
339 sdip += std::sqrt(dip2);
341 for (d = 0; d < DIM; d++)
343 sinp += dx[d]*dip[d];
344 sdinp += dx[d]*(dip[d] - refdip*dir[d]);
353 while (read_next_x(oenv, status, &t, x, box));
355 gmx_rmpbc_done(gpbc);
361 fprintf(stderr, "Average number of molecules within %g nm is %.1f\n",
362 rmax, static_cast<real>(ntot)/nf);
369 fprintf(stderr, "Average dipole: %f (D), std.dev. %f\n",
370 sdip, std::sqrt(sdip2-sqr(sdip)));
371 fprintf(stderr, "Average radial component of the dipole: %f (D)\n",
373 fprintf(stderr, "Average radial component of the polarization: %f (D)\n",
377 fp = xvgropen(opt2fn("-o", NFILE, fnm),
378 "Cumulative solvent distribution", "r (nm)", "molecules", oenv);
380 for (i = 0; i <= nbin; i++)
383 fprintf(fp, "%g %g\n", i*bw, nmol/nf);
387 do_view(oenv, opt2fn("-o", NFILE, fnm), NULL);