static PointSymmetry get_lattice_symmetry(SPGCONST Cell *cell,
const double symprec)
{
int i, j, k, num_sym;
int axes[3][3];
double lattice[3][3], min_lattice[3][3];
double metric[3][3], metric_orig[3][3];
PointSymmetry lattice_sym;
debug_print("get_lattice_symmetry:\n");
if (! lat_smallest_lattice_vector(min_lattice,
cell->lattice,
symprec)) {
goto err;
}
mat_get_metric(metric_orig, min_lattice);
num_sym = 0;
for (i = 0; i < 26; i++) {
for (j = 0; j < 26; j++) {
for (k = 0; k < 26; k++) {
set_axes(axes, i, j, k);
if (! ((mat_get_determinant_i3(axes) == 1) ||
(mat_get_determinant_i3(axes) == -1))) {
continue;
}
mat_multiply_matrix_di3(lattice, min_lattice, axes);
mat_get_metric(metric, lattice);
if (is_identity_metric(metric, metric_orig, symprec)) {
mat_copy_matrix_i3(lattice_sym.rot[num_sym], axes);
num_sym++;
}
if (num_sym > 48) {
warning_print("spglib: Too many lattice symmetries was found.\n");
warning_print(" Tolerance may be too large ");
warning_print("(line %d, %s).\n", __LINE__, __FILE__);
goto err;
}
}
}
}
lattice_sym.size = num_sym;
return transform_pointsymmetry(&lattice_sym,
cell->lattice,
min_lattice);
err:
lattice_sym.size = 0;
return lattice_sym;
}
static PointSymmetry get_lattice_symmetry(SPGCONST double cell_lattice[3][3],
const double symprec,
const double angle_symprec)
{
int i, j, k, attempt, num_sym;
double angle_tol;
int axes[3][3];
double lattice[3][3], min_lattice[3][3];
double metric[3][3], metric_orig[3][3];
PointSymmetry lattice_sym;
debug_print("get_lattice_symmetry:\n");
lattice_sym.size = 0;
if (! del_delaunay_reduce(min_lattice, cell_lattice, symprec)) {
goto err;
}
mat_get_metric(metric_orig, min_lattice);
angle_tol = angle_symprec;
for (attempt = 0; attempt < 100; attempt++) {
num_sym = 0;
for (i = 0; i < 26; i++) {
for (j = 0; j < 26; j++) {
for (k = 0; k < 26; k++) {
set_axes(axes, i, j, k);
if (! ((mat_get_determinant_i3(axes) == 1) ||
(mat_get_determinant_i3(axes) == -1))) {
continue;
}
mat_multiply_matrix_di3(lattice, min_lattice, axes);
mat_get_metric(metric, lattice);
if (is_identity_metric(metric, metric_orig, symprec, angle_tol)) {
if (num_sym > 47) {
angle_tol *= ANGLE_REDUCE_RATE;
warning_print("spglib: Too many lattice symmetries was found.\n");
warning_print(" Reduce angle tolerance to %f", angle_tol);
warning_print(" (line %d, %s).\n", __LINE__, __FILE__);
goto next_attempt;
}
mat_copy_matrix_i3(lattice_sym.rot[num_sym], axes);
num_sym++;
}
}
}
}
if (num_sym < 49 || angle_tol < 0) {
lattice_sym.size = num_sym;
return transform_pointsymmetry(&lattice_sym, cell_lattice, min_lattice);
}
next_attempt:
;
}
err:
debug_print("get_lattice_symmetry failed.\n");
return lattice_sym;
}
