Molecular Quadrupole Moment of Nitric Oxide

IT is known that nitric oxide is an interesting case of a three-electron bond. Taking the x -axis along the line of centres, the isolated atoms may be described as: The molecular orbital description of the molecule is then 1 : The two electrons in the MO (σ2 p x ) form a σ bond, the four in (π2 p y ), (π2 p z )—degenerate orbitals—form π bonds, whereas the remaining single electron in (π * 2 p z ) is antibonding.