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39 #include "gromacs/commandline/pargs.h"
40 #include "gromacs/fileio/tpxio.h"
41 #include "gromacs/fileio/trxio.h"
42 #include "gromacs/fileio/xvgr.h"
43 #include "gromacs/gmxana/gmx_ana.h"
44 #include "gromacs/gmxana/gstat.h"
45 #include "gromacs/legacyheaders/macros.h"
46 #include "gromacs/legacyheaders/viewit.h"
47 #include "gromacs/math/units.h"
48 #include "gromacs/math/vec.h"
49 #include "gromacs/pbcutil/pbc.h"
50 #include "gromacs/pbcutil/rmpbc.h"
51 #include "gromacs/topology/index.h"
52 #include "gromacs/utility/fatalerror.h"
53 #include "gromacs/utility/smalloc.h"
55 static void calc_com_pbc(int nrefat, t_topology *top, rvec x[], t_pbc *pbc,
56 atom_id index[], rvec xref, int ePBC)
58 const real tol = 1e-4;
64 /* First simple calculation */
67 for (m = 0; (m < nrefat); m++)
70 mass = top->atoms.atom[ai].m;
71 for (j = 0; (j < DIM); j++)
73 xref[j] += mass*x[ai][j];
77 svmul(1/mtot, xref, xref);
78 /* Now check if any atom is more than half the box from the COM */
85 for (m = 0; (m < nrefat); m++)
88 mass = top->atoms.atom[ai].m/mtot;
89 pbc_dx(pbc, x[ai], xref, dx);
90 rvec_add(xref, dx, xtest);
91 for (j = 0; (j < DIM); j++)
93 if (fabs(xtest[j]-x[ai][j]) > tol)
95 /* Here we have used the wrong image for contributing to the COM */
96 xref[j] += mass*(xtest[j]-x[ai][j]);
104 printf("COM: %8.3f %8.3f %8.3f iter = %d\n", xref[XX], xref[YY], xref[ZZ], iter);
112 void spol_atom2molindex(int *n, int *index, t_block *mols)
121 while (m < mols->nr && index[i] != mols->index[m])
127 gmx_fatal(FARGS, "index[%d]=%d does not correspond to the first atom of a molecule", i+1, index[i]+1);
129 for (j = mols->index[m]; j < mols->index[m+1]; j++)
131 if (i >= *n || index[i] != j)
133 gmx_fatal(FARGS, "The index group is not a set of whole molecules");
137 /* Modify the index in place */
140 printf("There are %d molecules in the selection\n", nmol);
145 int gmx_spol(int argc, char *argv[])
152 int nrefat, natoms, nf, ntot;
154 rvec *xtop, *x, xref, trial, dx = {0}, dip, dir;
159 atom_id **index, *molindex;
161 real rmin2, rmax2, rcut, rcut2, rdx2 = 0, rtry2, qav, q, dip2, invbw;
162 int nbin, i, m, mol, a0, a1, a, d;
163 double sdip, sdip2, sinp, sdinp, nmol;
166 gmx_rmpbc_t gpbc = NULL;
169 const char *desc[] = {
170 "[THISMODULE] analyzes dipoles around a solute; it is especially useful",
171 "for polarizable water. A group of reference atoms, or a center",
172 "of mass reference (option [TT]-com[tt]) and a group of solvent",
173 "atoms is required. The program splits the group of solvent atoms",
174 "into molecules. For each solvent molecule the distance to the",
175 "closest atom in reference group or to the COM is determined.",
176 "A cumulative distribution of these distances is plotted.",
177 "For each distance between [TT]-rmin[tt] and [TT]-rmax[tt]",
178 "the inner product of the distance vector",
179 "and the dipole of the solvent molecule is determined.",
180 "For solvent molecules with net charge (ions), the net charge of the ion",
181 "is subtracted evenly from all atoms in the selection of each ion.",
182 "The average of these dipole components is printed.",
183 "The same is done for the polarization, where the average dipole is",
184 "subtracted from the instantaneous dipole. The magnitude of the average",
185 "dipole is set with the option [TT]-dip[tt], the direction is defined",
186 "by the vector from the first atom in the selected solvent group",
187 "to the midpoint between the second and the third atom."
191 static gmx_bool bCom = FALSE, bPBC = FALSE;
192 static int srefat = 1;
193 static real rmin = 0.0, rmax = 0.32, refdip = 0, bw = 0.01;
195 { "-com", FALSE, etBOOL, {&bCom},
196 "Use the center of mass as the reference postion" },
197 { "-refat", FALSE, etINT, {&srefat},
198 "The reference atom of the solvent molecule" },
199 { "-rmin", FALSE, etREAL, {&rmin}, "Maximum distance (nm)" },
200 { "-rmax", FALSE, etREAL, {&rmax}, "Maximum distance (nm)" },
201 { "-dip", FALSE, etREAL, {&refdip}, "The average dipole (D)" },
202 { "-bw", FALSE, etREAL, {&bw}, "The bin width" }
206 { efTRX, NULL, NULL, ffREAD },
207 { efTPR, NULL, NULL, ffREAD },
208 { efNDX, NULL, NULL, ffOPTRD },
209 { efXVG, NULL, "scdist", ffWRITE }
211 #define NFILE asize(fnm)
213 if (!parse_common_args(&argc, argv, PCA_CAN_TIME | PCA_CAN_VIEW,
214 NFILE, fnm, asize(pa), pa, asize(desc), desc, 0, NULL, &oenv))
221 read_tpx_top(ftp2fn(efTPR, NFILE, fnm),
222 ir, box, &natoms, NULL, NULL, NULL, 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*sqrt(max_cutoff2(ir->ePBC, box));
255 nbin = (int)(rcut*invbw)+2;
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[(int)(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++)
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);
339 for (d = 0; d < DIM; d++)
341 sinp += dx[d]*dip[d];
342 sdinp += dx[d]*(dip[d] - refdip*dir[d]);
351 while (read_next_x(oenv, status, &t, x, box));
353 gmx_rmpbc_done(gpbc);
359 fprintf(stderr, "Average number of molecules within %g nm is %.1f\n",
360 rmax, (real)ntot/(real)nf);
367 fprintf(stderr, "Average dipole: %f (D), std.dev. %f\n",
368 sdip, sqrt(sdip2-sqr(sdip)));
369 fprintf(stderr, "Average radial component of the dipole: %f (D)\n",
371 fprintf(stderr, "Average radial component of the polarization: %f (D)\n",
375 fp = xvgropen(opt2fn("-o", NFILE, fnm),
376 "Cumulative solvent distribution", "r (nm)", "molecules", oenv);
378 for (i = 0; i <= nbin; i++)
381 fprintf(fp, "%g %g\n", i*bw, nmol/nf);
385 do_view(oenv, opt2fn("-o", NFILE, fnm), NULL);