Knowledge Bank

Excitation energies and oscillator strengths for the excited singlet states of $SF6$ are presented from Improved Virtual Orbital (IVO) calculations. The lowest state is the forbidden $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}T1g(1t1g\to 6alg)$ state, while the lowest allowed $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}T1u$ state corresponds to the $5t1u\to 6a1g$ transition. The $6alg$ orbital is found to be valence-like, while the $7a1g$ orbital corresponds to the 4s Rydberg orbital.