sqs_db.py 文件源码

def _parse_atat_lattice(lattice_in):
    """Parse an ATAT-style `lat.in` string.

    The parsed string will be in three groups: (Coordinate system) (lattice) (atoms)
    where the atom group is split up into subgroups, each describing the position and atom name
    """
    float_number = Regex(r'[-+]?[0-9]*\.?[0-9]+([eE][-+]?[0-9]+)?').setParseAction(lambda t: [float(t[0])])
    vector = Group(float_number + float_number + float_number)
    angles = vector
    vector_line = vector + Suppress(LineEnd())
    coord_sys = Group((vector_line + vector_line + vector_line) | (vector + angles + Suppress(LineEnd())))
    lattice = Group(vector + vector + vector)
    atom = Group(vector + Group(OneOrMore(Word(alphas + '_'))))
    atat_lattice_grammer = coord_sys + lattice + Group(OneOrMore(atom))
    # parse the input string and convert it to a POSCAR string
    return atat_lattice_grammer.parseString(lattice_in)