def get_metadata(data_dir=None):
    '''Obtain the metadata for all basis sets

    The metadata includes information such as the display name of the basis set,
    its versions, and what elements are included in the basis set

    The data is read from the METADATA.json file in the `data_dir` directory.

    Parameters
    ----------
    data_dir : str
        Data directory with all the basis set information. By default,
        it is in the 'data' subdirectory of this project.
    '''

    data_dir = fix_data_dir(data_dir)
    metadata_file = os.path.join(data_dir, "METADATA.json")
    return fileio.read_metadata(metadata_file)
Obtain the metadata for all basis sets

    The metadata includes information such as the display name of the basis set,
    its versions, and what elements are included in the basis set

    The data is read from the METADATA.json file in the `data_dir` directory.

    Parameters
    ----------
    data_dir : str
        Data directory with all the basis set information. By default,
        it is in the 'data' subdirectory of this project.