dwiddo / average-minimum-distance

    # atomic types

    asym_symbols = block._get_any(CIF_TAGS['atom_symbol'])

    if asym_symbols is None:

        warnings.warn('missing atomic types will be labelled 0')

        asym_types = [0] * len(asym_unit)

    else:

        asym_types = []

        for label in asym_symbols:

            if label in ('.', '?'):

                warnings.warn('missing atomic types will be labelled 0')

                num = 0

            else:

                sym = re.search(r'([A-Z][a-z]?)', label).group(0)

                if sym == 'D':

                    sym = 'H'

                num = ase_atomic_numbers[sym]

            asym_types.append(num)

    # find if sites have disorder if necassary

    has_disorder = []

    # atomic types

    for tag in CIF_TAGS['atom_symbol']:

        asym_symbols = odict.get(tag)

        if asym_symbols is not None:

            asym_types = []

            for label in asym_symbols:

                if label in ('.', '?'):

                    warnings.warn('missing atomic types will be labelled 0')

                    num = 0

                else:

                    sym = re.search(r'([A-Z][a-z]?)', label).group(0)

                    if sym == 'D':

                        sym = 'H'

                    # could use pymatgen here

                    num = ase_atomic_numbers[sym]

                asym_types.append(num)

            break

    else:

        warnings.warn('missing atomic types will be labelled 0')

        asym_types = [0] * len(asym_unit)