Hydrogen-Molecule Excited States: 1Πu

Abstract
The four lowest‐lying electronic states of molecular hydrogen of 1Πu symmetry have been calculated theoretically within the Born—Oppenheimer framework. The potential curves are quite regular, exhibiting maxima in the lowest state (2pΠu) at 8.85 bohr of about 120 cm−1 and the third state (4fΠu) at 5.9 bohr of about 715 cm−1. The potential curves have been used to calculate the vibrational—rotational energy levels for those states.