Theoretical study of the electronic structure of mono-bromide of lanthanum molecule including spin-orbit coupling effects

  • Yaman HamadeEmail author
  • Fadia Taher
  • Yehya Haidar
  • Ahmed Rhallabi
Original Paper


Among the family of lanthanide halides compounds, this work is devoted to the third halogen bromine. The presented lanthanum bromide LaBr molecule has a remarkable scientific interest regarding the other molecules because it presents few experimental studies and only one theoretical study. The theoretical electronic structure of the LaBr molecule is achieved by using the post-Hartree–Fock methods manifested by the complete active space self consistent field (CAS-SCF) method and the multi reference configuration interaction with single and double excitation (MRCI-SD) method. All of these calculations are performed via the quantum chemistry software MOLPRO. We predicted for the first time in the literature, 24 lowest-lying electronic states in the representation 2S+ 1Λ(±) and their corresponding components in the representation Ω(±) when taking into account the spin-orbit coupling (SOC), situated below 22,000 cm− 1. We calculated the spectroscopic constants for both cases (without/with SOC effects) related to the 13 singlet and 11 triplet states and for their components. We drew also in this paper the potential energy curves (PECs in a range of internuclear distance R varying from 2.00 to 4.22 Å.

Graphical Abstract

Potential energy curves for 13 singlet electronic states of LaBr


Diatomic molecules Ab initio methods Theoretical electronic states Spectroscopic constants Spin-orbit coupling 



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© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.MQMM lab associated to the research platformTR2NLebanese University, faculty of Engineering branch IIIRafic Hariri Campus-HadathLebanon
  2. 2.Institut des Matériaux Jean RouxelUniversité de NantesNantesFrance
  3. 3.Petrochemistry DepartmentLebanese University, Faculty of Engineering IIIRafic Hariri Campus-HadathLebanon

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