def test_piyzaz_chemical_formula():
""" Testing chemical formula for PIYZAZ in 111 and 222 packing"""
piyzaz111 = Molecule(read=piyzaz111_xyz)
assert piyzaz111.get_chemical_formula() == {'C': 8, 'Cd': 2}
piyzaz222 = Molecule(read=piyzaz222_xyz)
assert piyzaz222.get_chemical_formula() == {'C': 64, 'Cd': 16}
def test_benzene_chemical_formula():
""" Tests chemical formula for benzene molecule """
benzene = Molecule(read=benzene_xyz)
assert benzene.get_chemical_formula() == {'C': 6, 'H': 6}