NOTE:  the only difference between aromaticity
and antiaromaticity is rule #4






Rules for Antiaromaticity 

1. must be cyclic
2. must be planar
3. each atom of the ring must have a p orbital
and these p orbitals must be perpendicular to the
plane of the ring
4. Must contain 4n pi electrons (where n = 0, 1, 2, ...)