Editing Delocalized electron (section)

== Molecular orbitals ==
{{main|Molecular orbital}}
Standard [[ab initio quantum chemistry methods]] lead to [[molecular orbital|delocalized orbital]]s that, in general, extend over an entire molecule and have the symmetry of the molecule. [[Localized molecular orbitals|Localized orbitals]] may then be found as [[linear combination]]s of the delocalized orbitals, given by an appropriate [[unitary transformation]].

In the methane molecule, ab initio calculations show bonding character in four molecular orbitals, sharing the electrons uniformly among all five atoms. There are two orbital levels, a bonding molecular orbital formed from the 2s orbital on carbon and triply degenerate bonding molecular orbitals from each of the 2p orbitals on carbon. The localized sp<sup>3</sup> orbitals corresponding to each individual bond in [[valence bond theory]] can be obtained from a linear combination of the four molecular orbitals.