A DPF data analysis yields accurate analytic potentials for Li 2 a 3 Σ u + and Li 2 1 3 Σ g + that incorporate 3state mixing near the 1 3 Σ g + state asymptote
Abstract
A combinedisotopologue directpotentialfit (DPF) analysis of optical and photoassociation spectroscopy data for the a3Σu+ and 13Σg+ states of Li _{2} has yielded accurate analytic potential energy functions for both states. The recommended M3LR5,38.0(3) potential for the a3Σu+ state of ^{7,7}Li _{2} has a well depth of D_{e}=333.758(7) cm1 and an equilibrium distance of r_{e} = 4.17005(3) Å, and the associated scattering lengths are a_{SL} = 14.759(9) Å for ^{7,7}Li _{2} and a_{SL} = 1906(50) Å for ^{6,6}Li _{2}. In spite of a gap of more than 5200 cm ^{1} (between v(13Σg+)=7 and v(13Σg+)=62) for which there are no data, the DPF procedure can readily yield a 13Σg+ state potential energy function that accurately represents all of the available data and smoothly bridges this gap. For ^{7,7}Li _{2} our recommended M3LR6,33.6(9) potential has a well depth of D_{e}=7093.44(3) cm, an equilibrium distance of r_{e} = 3.06514(9) Å, and its longrange tail is defined by the lowest energy eigenvalue of a 3 × 3 matrix which takes into account the 3state mixing near its asymptote.
 Publication:

Journal of Molecular Spectroscopy
 Pub Date:
 July 2011
 DOI:
 10.1016/j.jms.2011.03.030
 arXiv:
 arXiv:1101.1361
 Bibcode:
 2011JMoSp.268..199D
 Keywords:

 Physics  Chemical Physics;
 Physics  Computational Physics;
 Quantum Physics
 EPrint:
 18 pages, 7 figures