Potential energy surface of the 1²A′ Li₂ + Li doublet ground state

Abstract

The lowest doublet electronic state for the lithium trimer (1 2 A ) is calculated for use in three-body scattering calculations using the valence electron FCI method with atomic cores represented using an effective core potential. It is shown that an accurate description of core-valence correlation is necessary for accurate calculations of molecular bond lengths, frequencies and dissociation energies. Interpolation between 1 2 A ab initio surface data points in a sparse grid is done using the global interpolant moving least squares method with a smooth radial data cutoff function included in the fitting weights and bivariate polynomials as a basis set. The Jahn-Teller splitting of the 1 2 E surface into the 1 2 A1 and 1 2 B2 states is investigated using a combination of both CASSCF and FCI levels of theory. Additionally, preliminary calculations of the 1 2 A surface are also presented using second order spin restricted open-shell Møller-Plesset perturbation theory.

Global accurate diabatic potential surfaces for the reaction H + Li2

“…The corresponding dissociation energy (D e ) is 8364.76 cm À1 . These results are in good agreement with Jason's results 49 (2.687Å and 8371.04 cm À1 ). In total, 19 vibrational bound levels are found for the Li 2 molecule.…”

Calculations of long-range three-body interactions forLi(2S2)−Li(2S2Yan1, Tang2, Zhou3 et al. 2016Phys. Rev. A71151View full textAdd to dashboardCite

“…Studies on three-lithium-atom system potential energy surfaces include the trimer system [35][36][37] and treatments of the atom-dimer configuration within the context of a global trimer potential energy surface [38][39][40]. Motivated by ultra-cold science, some recent studies on lithium focused on generation of improved global potential energy surfaces for the trimer [41][42][43] or addressed the atom-dimer configuration in further detail [44][45][46], with emphasis on the configuration of a Li(2 2 S) atom interacting with a (bound) lithium dimer for applications to scattering processes [44,47,48]. Such investigations on long-range interactions for three-lithium-atom systems continue to support applications to atom-dimer scattering at thermal energies [49] and to atom-dimer photoassociation in the ultra-cold energy domain [45].…”

Structure and thermochemistry ofK2Rb, KRb2, and

“…Theoretical work on electronic structure of few-body alkali systems has been limited to lighter homonuclear trimers, in particular, doublet [10] and quartet [11] Li 3 , doublet K 3 [12], and quartet Na 3 [13]. The recent work ofŻuchowski and Hutson [14] has characterized the atomization energy of the alkali-metal homo-and heteronuclear triatomic species formed from Li, Na, K, Rb, and Cs.…”