Knowledge Bank

The inner wall of a recently $calculated1,2$ potential of the $A2\pi u$ state of the $O2-$ ion shows a curious flattening. To explain and correct this, various aspects of the model used for the MCSCF calculations are analyzed. The interesting finding is that at distances $\le 2.2$ bohrs, a Rydberg-like $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\pi u$ state has a lower energy than the lowest valence $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\pi u$ state.