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41 #include "gromacs/legacyheaders/macros.h"
43 #include "gromacs/legacyheaders/viewit.h"
44 #include "gromacs/pbcutil/pbc.h"
45 #include "gromacs/topology/index.h"
46 #include "gromacs/fileio/tpxio.h"
47 #include "gromacs/fileio/trxio.h"
48 #include "gromacs/math/units.h"
51 #include "gromacs/commandline/pargs.h"
52 #include "gromacs/fileio/xvgr.h"
53 #include "gromacs/math/vec.h"
54 #include "gromacs/pbcutil/rmpbc.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 (fabs(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[])
155 int nrefat, natoms, nf, ntot;
157 rvec *xtop, *x, xref, trial, dx = {0}, dip, dir;
162 atom_id **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 = NULL;
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."
194 static gmx_bool bCom = FALSE, bPBC = 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},
199 "Use the center of mass as the reference postion" },
200 { "-refat", FALSE, etINT, {&srefat},
201 "The reference atom of the solvent molecule" },
202 { "-rmin", FALSE, etREAL, {&rmin}, "Maximum distance (nm)" },
203 { "-rmax", FALSE, etREAL, {&rmax}, "Maximum distance (nm)" },
204 { "-dip", FALSE, etREAL, {&refdip}, "The average dipole (D)" },
205 { "-bw", FALSE, etREAL, {&bw}, "The bin width" }
209 { efTRX, NULL, NULL, ffREAD },
210 { efTPX, NULL, NULL, ffREAD },
211 { efNDX, NULL, NULL, ffOPTRD },
212 { efXVG, NULL, "scdist.xvg", ffWRITE }
214 #define NFILE asize(fnm)
216 if (!parse_common_args(&argc, argv, PCA_CAN_TIME | PCA_CAN_VIEW,
217 NFILE, fnm, asize(pa), pa, asize(desc), desc, 0, NULL, &oenv))
224 read_tpx_top(ftp2fn(efTPX, NFILE, fnm),
225 ir, box, &natoms, NULL, NULL, NULL, top);
227 /* get index groups */
228 printf("Select a group of reference particles and a solvent group:\n");
232 get_index(&top->atoms, ftp2fn_null(efNDX, NFILE, fnm), 2, isize, index, grpname);
245 spol_atom2molindex(&(isize[1]), index[1], &(top->mols));
248 /* initialize reading trajectory: */
249 natoms = read_first_x(oenv, &status, ftp2fn(efTRX, NFILE, fnm), &t, &x, box);
251 rcut = 0.99*sqrt(max_cutoff2(ir->ePBC, box));
258 nbin = (int)(rcut*invbw)+2;
271 molindex = top->mols.index;
272 atom = top->atoms.atom;
274 gpbc = gmx_rmpbc_init(&top->idef, ir->ePBC, natoms);
276 /* start analysis of trajectory */
279 /* make molecules whole again */
280 gmx_rmpbc(gpbc, natoms, box, x);
282 set_pbc(&pbc, ir->ePBC, box);
285 calc_com_pbc(nrefat, top, x, &pbc, index[0], xref, ir->ePBC);
288 for (m = 0; m < isize[1]; m++)
292 a1 = molindex[mol+1];
293 for (i = 0; i < nrefgrp; i++)
295 pbc_dx(&pbc, x[a0+srefat], bCom ? xref : x[index[0][i]], trial);
296 rtry2 = norm2(trial);
297 if (i == 0 || rtry2 < rdx2)
299 copy_rvec(trial, dx);
305 hist[(int)(sqrt(rdx2)*invbw)+1]++;
307 if (rdx2 >= rmin2 && rdx2 < rmax2)
312 for (a = a0; a < a1; a++)
317 for (a = a0; a < a1; a++)
320 for (d = 0; d < DIM; d++)
325 for (d = 0; d < DIM; d++)
329 for (a = a0+1; a < a0+3; a++)
331 for (d = 0; d < DIM; d++)
333 dir[d] += 0.5*x[a][d];
338 svmul(ENM2DEBYE, dip, dip);
342 for (d = 0; d < DIM; d++)
344 sinp += dx[d]*dip[d];
345 sdinp += dx[d]*(dip[d] - refdip*dir[d]);
354 while (read_next_x(oenv, status, &t, x, box));
356 gmx_rmpbc_done(gpbc);
362 fprintf(stderr, "Average number of molecules within %g nm is %.1f\n",
363 rmax, (real)ntot/(real)nf);
370 fprintf(stderr, "Average dipole: %f (D), std.dev. %f\n",
371 sdip, sqrt(sdip2-sqr(sdip)));
372 fprintf(stderr, "Average radial component of the dipole: %f (D)\n",
374 fprintf(stderr, "Average radial component of the polarization: %f (D)\n",
378 fp = xvgropen(opt2fn("-o", NFILE, fnm),
379 "Cumulative solvent distribution", "r (nm)", "molecules", oenv);
381 for (i = 0; i <= nbin; i++)
384 fprintf(fp, "%g %g\n", i*bw, nmol/nf);
388 do_view(oenv, opt2fn("-o", NFILE, fnm), NULL);