Antibonding molecular orbital

H2 1sσ* antibonding molecular orbital

In theoretical chemistry, an antibonding orbital is a type of molecular orbital that weakens the chemical bond between two atoms and helps to raise the energy of the molecule relative to the separated atoms. Such an orbital has one or more nodes in the bonding region between the nuclei. The density of the electrons in the orbital is concentrated outside the bonding region and acts to pull one nucleus away from the other and tends to cause mutual repulsion between the two atoms.[1][2] This is in contrast to a bonding molecular orbital, which has a lower energy than that of the separate atoms, and is responsible for chemical bonds.

  1. ^ Atkins P. and de Paula J. Atkins Physical Chemistry. 8th ed. (W.H. Freeman 2006), p.371 ISBN 0-7167-8759-8
  2. ^ Miessler G.L. and Tarr D.A., Inorganic Chemistry 2nd ed. (Prentice-Hall 1999), p.111 ISBN 0-13-841891-8