Search for vasprun files from the current directory.

    The precedence order for file locations is:

      1. First search for folders named: 'split-0*'
      2. Else, look in the current directory.

    The split folder names should always be zero based, therefore easily
    sortable.

def find_vasprun_files():
    """Search for vasprun files from the current directory.

    The precedence order for file locations is:

      1. First search for folders named: 'split-0*'
      2. Else, look in the current directory.

    The split folder names should always be zero based, therefore easily
    sortable.
    """
    folders = glob.glob('split-*')
    folders = sorted(folders) if folders else ['.']

    filenames = []
    for fol in folders:
        vr_file = os.path.join(fol, 'vasprun.xml')
        vr_file_gz = os.path.join(fol, 'vasprun.xml.gz')

        if os.path.exists(vr_file):
            filenames.append(vr_file)
        elif os.path.exists(vr_file_gz):
            filenames.append(vr_file_gz)
        else:
            logging.error('ERROR: No vasprun.xml found in {}!'.format(fol))
            sys.exit()

    return filenames