title: A variational algebraic method used to study the full vibrational spectra and dissociation energies of some specific diatomic systems.
abstract: The algebraic method (AM) proposed by Sun et al. is improved to be a variational AM (VAM) to offset the possible experimental errors and to adapt to the individual energy expansion nature of different molecular systems. The VAM is used to study the full vibrational spectra {Eυ} and the dissociation energies De of (4)HeH(+)-X(1)Σ(+), (7)Li2-1(3)Δg,Na2-C(1)Πu,NaK-7(1)Π, Cs2-B(1)Πu and (79)Br2-β1g((3)P2) diatomic electronic states. The results not only precisely reproduce all known experimental vibrational energies, but also predict correct dissociation energies and all unknown high-lying levels that may not be given by the original AM or other numerical methods or experimental methods. The analyses and the skill suggested here might be useful for other numerical simulations and theoretical fittings using known data that may carry inevitable errors.
authors.affiliation: School of Physics, Sichuan University, Chengdu, Sichuan 610065, PR China; School of Physics and Chemistry, Research Center for Advanced Computation, Xihua University, Chengdu, Sichuan 610039, PR China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Weiguo
authors.initials: W
authors.lastname: Sun
authors.forename: Jia
authors.initials: J
authors.lastname: Fu
authors.forename: Qunchao
authors.initials: Q
authors.lastname: Fan
authors.forename: Jie
authors.initials: J
authors.lastname: Ma
authors.forename: Liantuan
authors.initials: L
authors.lastname: Xiao
authors.forename: Suotang
authors.initials: S
authors.lastname: Jia
authors.forename: Hao
authors.initials: H
authors.lastname: Feng
authors.forename: Huidong
authors.initials: H
authors.lastname: Li
mesh_terms: D003198:Computer Simulation; D017377:Diatoms / Q000737:chemistry*; D004583:Electrons; D008433:Mathematics; D013057:Spectrum Analysis; D013816:Thermodynamics; D014732:Vibration
keywords: Algebraic method; Dissociation energy; Error amplification; Variation; Vibrational level