/*! \libinternal \brief Compute greatest common divisor of n1 and n2
* if they are positive.
*
* If only one of n1 and n2 is positive, then return it.
* If neither n1 or n2 is positive, then return -1. */
static int
greatest_common_divisor_if_positive(int n1, int n2)
{
if (0 >= n1)
{
return (0 >= n2) ? -1 : n2;
}
if (0 >= n2)
{
return n1;
}
/* We have a non-trivial greatest common divisor to compute. */
return gmx_greatest_common_divisor(n1, n2);
}
int gmx_genion(int argc, char *argv[])
{
const char *desc[] = {
"[THISMODULE] randomly replaces solvent molecules with monoatomic ions.",
"The group of solvent molecules should be continuous and all molecules",
"should have the same number of atoms.",
"The user should add the ion molecules to the topology file or use",
"the [TT]-p[tt] option to automatically modify the topology.[PAR]",
"The ion molecule type, residue and atom names in all force fields",
"are the capitalized element names without sign. This molecule name",
"should be given with [TT]-pname[tt] or [TT]-nname[tt], and the",
"[TT][molecules][tt] section of your topology updated accordingly,",
"either by hand or with [TT]-p[tt]. Do not use an atom name instead!",
"[PAR]Ions which can have multiple charge states get the multiplicity",
"added, without sign, for the uncommon states only.[PAR]",
"For larger ions, e.g. sulfate we recommended using [gmx-insert-molecules]."
};
const char *bugs[] = {
"If you specify a salt concentration existing ions are not taken into "
"account. In effect you therefore specify the amount of salt to be added.",
};
static int p_num = 0, n_num = 0, p_q = 1, n_q = -1;
static const char *p_name = "NA", *n_name = "CL";
static real rmin = 0.6, conc = 0;
static int seed = 1993;
static gmx_bool bNeutral = FALSE;
static t_pargs pa[] = {
{ "-np", FALSE, etINT, {&p_num}, "Number of positive ions" },
{ "-pname", FALSE, etSTR, {&p_name}, "Name of the positive ion" },
{ "-pq", FALSE, etINT, {&p_q}, "Charge of the positive ion" },
{ "-nn", FALSE, etINT, {&n_num}, "Number of negative ions" },
{ "-nname", FALSE, etSTR, {&n_name}, "Name of the negative ion" },
{ "-nq", FALSE, etINT, {&n_q}, "Charge of the negative ion" },
{ "-rmin", FALSE, etREAL, {&rmin}, "Minimum distance between ions" },
{ "-seed", FALSE, etINT, {&seed}, "Seed for random number generator" },
{ "-conc", FALSE, etREAL, {&conc},
"Specify salt concentration (mol/liter). This will add sufficient ions to reach up to the specified concentration as computed from the volume of the cell in the input [REF].tpr[ref] file. Overrides the [TT]-np[tt] and [TT]-nn[tt] options." },
{ "-neutral", FALSE, etBOOL, {&bNeutral}, "This option will add enough ions to neutralize the system. These ions are added on top of those specified with [TT]-np[tt]/[TT]-nn[tt] or [TT]-conc[tt]. "}
};
t_topology top;
rvec *x, *v;
real vol, qtot;
matrix box;
t_atoms atoms;
t_pbc pbc;
int *repl, ePBC;
atom_id *index;
char *grpname;
gmx_bool *bSet;
int i, nw, nwa, nsa, nsalt, iqtot;
gmx_output_env_t *oenv;
gmx_rng_t rng;
t_filenm fnm[] = {
{ efTPR, NULL, NULL, ffREAD },
{ efNDX, NULL, NULL, ffOPTRD },
{ efSTO, "-o", NULL, ffWRITE },
{ efTOP, "-p", "topol", ffOPTRW }
};
#define NFILE asize(fnm)
if (!parse_common_args(&argc, argv, 0, NFILE, fnm, asize(pa), pa,
asize(desc), desc, asize(bugs), bugs, &oenv))
{
return 0;
}
/* Check input for something sensible */
if ((p_num < 0) || (n_num < 0))
{
gmx_fatal(FARGS, "Negative number of ions to add?");
}
if (conc > 0 && (p_num > 0 || n_num > 0))
{
fprintf(stderr, "WARNING: -conc specified, overriding -nn and -np.\n");
}
/* Read atom positions and charges */
read_tps_conf(ftp2fn(efTPR, NFILE, fnm), &top, &ePBC, &x, &v, box, FALSE);
atoms = top.atoms;
/* Compute total charge */
qtot = 0;
for (i = 0; (i < atoms.nr); i++)
{
qtot += atoms.atom[i].q;
}
iqtot = std::round(qtot);
if (conc > 0)
{
/* Compute number of ions to be added */
vol = det(box);
nsalt = std::round(conc*vol*AVOGADRO/1e24);
p_num = abs(nsalt*n_q);
n_num = abs(nsalt*p_q);
}
if (bNeutral)
{
int qdelta = p_num*p_q + n_num*n_q + iqtot;
/* Check if the system is neutralizable
* is (qdelta == p_q*p_num + n_q*n_num) solvable for p_num and n_num? */
int gcd = gmx_greatest_common_divisor(n_q, p_q);
if ((qdelta % gcd) != 0)
{
gmx_fatal(FARGS, "Can't neutralize this system using -nq %d and"
" -pq %d.\n", n_q, p_q);
}
while (qdelta != 0)
{
while (qdelta < 0)
{
p_num++;
qdelta += p_q;
}
while (qdelta > 0)
{
n_num++;
qdelta += n_q;
}
}
}
if ((p_num == 0) && (n_num == 0))
{
fprintf(stderr, "No ions to add, will just copy input configuration.\n");
}
else
{
printf("Will try to add %d %s ions and %d %s ions.\n",
p_num, p_name, n_num, n_name);
printf("Select a continuous group of solvent molecules\n");
get_index(&atoms, ftp2fn_null(efNDX, NFILE, fnm), 1, &nwa, &index, &grpname);
for (i = 1; i < nwa; i++)
{
if (index[i] != index[i-1]+1)
{
gmx_fatal(FARGS, "The solvent group %s is not continuous: "
"index[%d]=%d, index[%d]=%d",
grpname, i, index[i-1]+1, i+1, index[i]+1);
}
}
nsa = 1;
while ((nsa < nwa) &&
(atoms.atom[index[nsa]].resind ==
atoms.atom[index[nsa-1]].resind))
{
nsa++;
}
if (nwa % nsa)
{
gmx_fatal(FARGS, "Your solvent group size (%d) is not a multiple of %d",
nwa, nsa);
}
nw = nwa/nsa;
fprintf(stderr, "Number of (%d-atomic) solvent molecules: %d\n", nsa, nw);
if (p_num+n_num > nw)
{
gmx_fatal(FARGS, "Not enough solvent for adding ions");
}
if (opt2bSet("-p", NFILE, fnm))
{
update_topol(opt2fn("-p", NFILE, fnm), p_num, n_num, p_name, n_name, grpname);
}
snew(bSet, nw);
snew(repl, nw);
snew(v, atoms.nr);
snew(atoms.pdbinfo, atoms.nr);
set_pbc(&pbc, ePBC, box);
if (seed == 0)
{
rng = gmx_rng_init(gmx_rng_make_seed());
}
else
{
rng = gmx_rng_init(seed);
}
/* Now loop over the ions that have to be placed */
while (p_num-- > 0)
{
insert_ion(nsa, &nw, bSet, repl, index, x, &pbc,
1, p_q, p_name, &atoms, rmin, rng);
}
while (n_num-- > 0)
{
insert_ion(nsa, &nw, bSet, repl, index, x, &pbc,
-1, n_q, n_name, &atoms, rmin, rng);
}
gmx_rng_destroy(rng);
fprintf(stderr, "\n");
if (nw)
{
sort_ions(nsa, nw, repl, index, &atoms, x, p_name, n_name);
}
sfree(atoms.pdbinfo);
atoms.pdbinfo = NULL;
}
write_sto_conf(ftp2fn(efSTO, NFILE, fnm), *top.name, &atoms, x, NULL, ePBC, box);
return 0;
}
