Nonbonding orbital
= Nonbonding orbital
A <molecular orbital> with little or no net bonding interaction between the atoms in the stated orbital model. A symmetry-isolated <atomic orbital> can be exactly nonbonding in a minimal basis: the out-of-plane nitrogen $2p_z$ orbital in planar <ammonia> has no matching hydrogen <symmetry orbital>. A mainly localized <lone pair> can acquire bonding admixture when a distortion permits additional mixing.