def _get_element_and_line(xray_line):
    """
    Returns the element name and line character for a particular X-ray line as
    a tuple.

    By example, if xray_line = 'Mn_Ka' this function returns ('Mn', 'Ka')
    """
    lim = xray_line.find('_')
    if lim == -1:
        raise ValueError('Invalid xray-line: %' % xray_line)
    return xray_line[:lim], xray_line[lim + 1:]
