Fig. 8-8.  Contour maps of the molecular orbital charge densities for O₂ at the equilibrium internuclear distance of 2.282 au. Only one component of the Ip_g and 1p_u orbitals is shown. All the maps are for doubly-occupied orbitals with the exception of that for 1p_g for which each component of the doubly-degenerate orbital contains a single electron. The nodes are indicated by dashed lines. Click here for contour values.