Theoretical study of the electronic structure of mono-chloride of lanthanum molecule including spin-orbit coupling effect

Abstract

Our investigation is devoted to the theoretical study of the low-lying electronic structure of the LaCl molecule by using ab initio quantum methods. We are concerned with several methods such as the complete active space-self consistent field (CAS-SCF) and the multi reference of configuration interaction (MRCI + Q) methods. These methods are applied for the purpose of drawing the potential energy curves (PECs) and calculating the molecular spectroscopic constants for a given number of electronic states of singlet and triplet multiplicity. We count 26 Λ electronic states located below 24,000 cm neglecting the spin-orbit effects and 47 Ω components taken into consideration these effects. Our calculations are performed via the quantum ab initio package MOLPRO (Werner and Knowles 2000). Graphical Abstract A new set of low-lying electronic states on the theoretical energetic level diagram for the LaCl molecule among the first four lanthanum monhalides.

Observation of Selectively Populated Monohalide Excited States from the Reactions of Group 3 Metal (Sc, Y, and La) Monomers and Dimers with Halogen-Containing Molecules

“…The calculated geometry parameters, vibrational frequencies, and BDEs are given in Table with the components for calculating the BDEs in the Supporting Information. The calculated bond distances and harmonic vibrational frequencies are in good agreement with the available experimental data − and prior computational studies. ,− Our calculated bond lengths are within <1 pm of the experimental values, and the calculated ω e values are within 5 cm –1 of the experiment. ,− , Additional high-level CCSD­(T) and multireference configuration interaction (MRCI) calculations of the ω e for ScCl, ScBr, and LaCl are consistent with our results.…”

“… a Reference (theory, CISD/CPF). b Reference (theory, MRCI + outer core + first-order DK). c Reference (theory, CCSDT/CBS). d Reference (theory, MRCI/RCCSD­(T)). e Reference (theory, CASSCF/MRCI). f Reference (theory, CASSCF/MRCI). g Reference (theory, CASSCF/MRCI). h Reference (theory, CASSCF/MRCI). i Reference (theory, MCPF). j Reference (theory, CAS-SCF/MRCI). k Reference (theory, DFT). l Reference (theory, DFT). m Reference (theory, CASSCF/MRCI). n Reference (theory, CAS-SCF/MRCI). o Reference (theory, CASSCF/MRCI). p Reference (theory, CASSCF/MRCI). q Reference (theory, CASSCF/MRCI). r Reference (theory, CASSCF/MRCI). s Reference (experimental compilation). t Reference (near IR Fluor). u Reference (Fluor exc IR). v Reference (microwave spectra, estimate D e = ω e 2 /4ω e χ e ). w Reference (mass spectrometry, M + BaF = MF + Ba, M + MF 2 = 2 MF). x Reference (experimental compilation). y Reference (mass spectrometry at 298 K). z Reference (estimated values). …”

“…We consider the chemiluminescent emission characterizing 16 reactions of the group 3 metals Sc, Y, and La and their dimers with F 2 , ClF, and Cl 2 as well as SF 6 ; Sc with Br 2 and ICl; Y with Br 2 and IBr; and Sc 2 and Y 2 with Cl and Br atoms. The available spectroscopic data from experiments ,,,,− ,− and calculations ,,− ,− ,− ,− are given in Tables – .…”

“… a Reference (theory, CASSCF/MRCI). b Reference (theory, CASSCF/MRCI). c Reference (theory, CASSCF/MRCI). d Reference (theory, CASSCF/MRCI). e T 0 . f Labeled c 1 3 Δ 1 in reference. g Assigned originally as B 1 Π. …”