static int get_hall_number( double origin_shift[3],
double conv_lattice[3][3],
Centering * centering,
SPGCONST Cell * primitive,
SPGCONST Symmetry * symmetry,
const double symprec )
{
int pg_num, attempt, hall_number=0;
double tolerance;
Symmetry * sym_reduced;
tolerance = symprec;
pg_num = ptg_get_pointgroup_number( symmetry );
if ( pg_num > -1 ) {
hall_number = get_hall_number_local( origin_shift,
conv_lattice,
centering,
primitive,
symmetry,
symprec );
if ( hall_number > 0 ) { goto ret; }
}
/* Reduce tolerance and search hall symbol again when hall symbol */
/* could not be found by the given tolerance. */
/* The situation this happens is that symmetry operations found */
/* don't match any of hall symbol database due to tricky */
/* displacements of atoms from the exact points. */
for ( attempt = 0; attempt < 100; attempt++ ) {
tolerance *= REDUCE_RATE;
sym_reduced = sym_reduce_operation( primitive, symmetry, tolerance );
pg_num = ptg_get_pointgroup_number( sym_reduced );
if ( pg_num > -1 ) {
hall_number = get_hall_number_local( origin_shift,
conv_lattice,
centering,
primitive,
sym_reduced,
symprec );
if ( hall_number > 0 ) {
sym_free_symmetry( sym_reduced );
warning_print("spglib: Tolerance to find Hall symbol was changed to %f\n", tolerance);
goto ret;
}
}
sym_free_symmetry( sym_reduced );
}
warning_print("spglib: Iterative attempt to find Hall symbol was failed.");
ret:
return hall_number;
}
static int get_hall_number_local_iteration(double origin_shift[3],
double conv_lattice[3][3],
SPGCONST Cell * primitive,
SPGCONST Symmetry * symmetry,
const double symprec)
{
int attempt, pg_num, hall_number=0;
double tolerance;
Symmetry * sym_reduced;
debug_print("get_hall_number_local_iteration:\n");
tolerance = symprec;
for (attempt = 0; attempt < 100; attempt++) {
tolerance *= REDUCE_RATE;
debug_print(" Attempt %d tolerance = %f\n", attempt, tolerance);
sym_reduced = sym_reduce_operation(primitive, symmetry, tolerance);
pg_num = ptg_get_pointgroup_number(sym_reduced);
if (pg_num > -1) {
hall_number = get_hall_number_local(origin_shift,
conv_lattice,
primitive,
sym_reduced,
symprec);
if (hall_number > 0) {
sym_free_symmetry(sym_reduced);
break;
}
}
sym_free_symmetry(sym_reduced);
}
#ifdef SPGWARNING
if (hall_number == 0) {
warning_print("spglib: Iterative attempt with sym_reduce_operation to find Hall symbol failed.\n");
}
#endif
return hall_number;
}
static int get_hall_number(double origin_shift[3],
double conv_lattice[3][3],
SPGCONST Cell * primitive,
SPGCONST Symmetry * symmetry,
const double symprec)
{
int pg_num, hall_number=0;
debug_print("get_hall_number:\n");
pg_num = ptg_get_pointgroup_number(symmetry);
if (pg_num > -1) {
hall_number = get_hall_number_local(origin_shift,
conv_lattice,
primitive,
symmetry,
symprec);
if (hall_number > 0) {
goto ret;
}
}
/* Reduce tolerance and search hall symbol again when hall symbol */
/* could not be found by the given tolerance. */
/* The situation this happens is that symmetry operations found */
/* don't match any of hall symbol database due to tricky */
/* displacements of atoms from the exact points. */
hall_number = get_hall_number_local_iteration(origin_shift,
conv_lattice,
primitive,
symmetry,
symprec);
ret:
return hall_number;
}