def symsplit(item):
    """
    Splits symmetric molecule atom mapping expression into its component parts.
    Returns a list of atom mappings in the symmetric molecule.

    For example:

    symsplit('(abc;cba)') = ['abc','cba']
    """

    # Removing white space
    tmp=item.replace(' ','')
    # checking format      
    if (item[0] != '(') or (item[-1] != ')'):
        print("error in", item,"!\n")
    else:
        tmp=tmp[1:-1].split(';')
        # checking sizes to make sure they are all the same
        sizet=len(tmp[0])
        for t in tmp[1:]:
            if len(t) != sizet:
                print("Sizes of the symmetric molecules are not the same!\n")
                print(tmp)
    return tmp