Electronic structure of the Li2 [X 1Σmath image] Li [2p] excited 2A″ surface



Potential energy surface calculations are reported for the lowest 2A″ surface arising from the Li2 [X 1Σmath image] + Li* [2P] interaction. The 2A″ surface with Cs symmetry, which correlates to the 2B1 surface in C2v symmetry and to the 2Pi surface in C∞v, has been calculated using second order restricted open-shell Møller–Plesset theory. Our calculated surface has a minimum in C2v symmetry that resembles the ground state surface but does not exhibit the Jahn–Teller splitting found for the ground state potential energy surface. Dipole transition moments are calculated in C2v geometry near the 2A″ minima using the internally contracted multireference singles and doubles configuration interaction theory. We have also analyzed the long range behavior of this 2A″ surface by fitting the ab initio calculations at long range with a functional series of the form ±Cn/Rn. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009