Sent to CCL by: "Jim Kress" [ccl_nospam- -kressworks.com] If you use NBO on your system, it will automatically classify all the orbitals with respect to their sigma, pi, n - bonding and antibonding (*) characteristics. Then you will automatically be able to find the information you desire, since you have the orbital numbers. http://www.chem.wisc.edu/~nbo5/ Jim