antibonding molecular orbital

https://doi.org/10.1351/goldbook.AT06988
The @M03996@ whose occupation by electrons decreases the total bonding (as usual, increases the total energy) of a molecule. The energy level of an antibonding MO lies higher than the average of the @V06588@ atomic orbitals of the atoms constituting the molecule.
Source:
PAC, 1999, 71, 1919. (Glossary of terms used in theoretical organic chemistry) on page 1923 [Terms] [Paper]