Exemple #1
0
def read_cif(filename):
    """
    read the cif, mainly for pyxtal cif output
    Be cautious in using it to read other cif files

    Args:
        filename: path of the structure file 

    Return:
        pyxtal structure
    """
    species = []
    coords = []
    with open(filename, 'r') as f:
        lines = f.readlines()
        for i, line in enumerate(lines):
            if line.startswith('_symmetry_Int_Tables_number'):
                sg = int(line.split()[-1])
            elif line.startswith('_cell_length_a'):
                a = float(lines[i].split()[-1])
                b = float(lines[i+1].split()[-1])
                c = float(lines[i+2].split()[-1])
                alpha = float(lines[i+3].split()[-1])
                beta = float(lines[i+4].split()[-1])
                gamma = float(lines[i+5].split()[-1])
            elif line.startswith('_symmetry_cell_setting'):
                lat_type = line.split()[-1]
            elif line.startswith('_symmetry_space_group_name_H-M '):
                symbol = line.split()[-1]
                if eval(symbol) in ["Pn", "P21/n", "C2/n"]:
                    diag = True
                else:
                    diag = False

            elif line.find('_atom_site') >= 0:
                s = i
                while True:
                    s += 1
                    if lines[s].find('_atom_site') >= 0:
                        pass
                    elif len(lines[s].split()) <= 3:
                        break
                    else:
                        tmp = lines[s].split()
                        pos = [float(tmp[-4]), float(tmp[-3]), float(tmp[-2])]
                        species.append(tmp[0])
                        coords.append(pos)
                break

    wp0 = Group(sg)[0]
    lattice = Lattice.from_para(a, b, c, alpha, beta, gamma, lat_type)
    sites = []
    for specie, coord in zip(species, coords):
        pt, wp, _ = WP_merge(coord, lattice.matrix, wp0, tol=0.1)
        sites.append(atom_site(wp, pt, specie, diag))
    return lattice, sites
Exemple #2
0
from pymatgen.core.structure import Molecule
import pymatgen.analysis.structure_matcher as sm
from pymatgen.symmetry.analyzer import SpacegroupAnalyzer
from pymatgen.core.operations import SymmOp

from pyxtal import pyxtal
from pyxtal.lattice import Lattice
from pyxtal.symmetry import Group, Wyckoff_position, get_wyckoffs
from pyxtal.wyckoff_site import WP_merge
from pyxtal.XRD import Similarity
from pyxtal.operations import get_inverse

cif_path = resource_filename("pyxtal", "database/cifs/")
l0 = Lattice.from_matrix([[4.08, 0, 0], [0, 9.13, 0], [0, 0, 5.50]])
l1 = Lattice.from_matrix([[4.08, 0, 0], [0, 9.13, 0], [0, 0, 5.50]])
l2 = Lattice.from_para(4.08, 9.13, 5.50, 90, 90, 90)
l3 = Lattice.from_para(4.08, 7.13, 5.50, 90, 38, 90, ltype="monoclinic")
wp1 = Wyckoff_position.from_group_and_index(36, 0)
wp2 = Wyckoff_position.from_group_and_index(36, "4a")


class TestGroup(unittest.TestCase):
    def test_list_wyckoff_combinations(self):
        g = Group(64)
        a1, _ = g.list_wyckoff_combinations([4, 2])
        self.assertTrue(a1 is None)
        a2, _ = g.list_wyckoff_combinations([4, 8], quick=False)
        self.assertTrue(len(a2) == 8)


class TestOptLat(unittest.TestCase):