Editing Quantum chemistry (section)

=== Valence bond theory ===
{{main|Valence bond theory}}

As mentioned above, Heitler and London's method was extended by Slater and Pauling to become the valence-bond (VB) 
method. In this method, attention is primarily devoted to the pairwise interactions between atoms, and this method therefore correlates closely with classical chemists' drawings of [[chemical bond|bonds]]. It focuses on how the atomic orbitals of an atom combine to give individual chemical bonds when a molecule is formed, incorporating the two key concepts of [[orbital hybridization]] and [[resonance (chemistry)|resonance]].<ref>{{Cite book |last1=Shaik |first1=S.S. |title=A Chemist's Guide to Valence Bond Theory |last2=Hiberty |first2=P.C. |publisher=Wiley-Interscience |year=2007 |isbn=978-0470037355}}</ref>