@Test(expected = NullPointerException.class)
public void testCovalentPlatinum() throws Exception {

    SmilesParser sp = new SmilesParser(DefaultChemObjectBuilder.getInstance());
    IAtomContainer mol = sp.parseSmiles("CC1CN[Pt]2(N1)OC(=O)C(C)P(=O)(O)O2");
    descriptor.calculate(mol).getValue();
}