Ab initio study of the lowest-lying electronic states of LuCl molecules

Laser cooling with intermediate state of spin-orbit coupling of LuF molecule

This work presents a theoretical study of the laser cooling feasibility of the molecule LuF, in the fine structure level of approximation. An ab-initio complete active space self-consistent field (CASSCF)/MRCI with Davidson correction calculation has been done in the Λ^(±) and Ω^(±) representations. The corresponding adiabatic potential energy curves and spectroscopic parameters have been investigated for the low-lying electronic states. The calculated values of the internuclear distances of the X³Σ₀₊ and (1)³Π₀₊ states show the candidacy of the molecule LuF for direct laser cooling. Since the existence of the intermediate (1)³Δ₁ state cannot be ignored, the investigation has been done by taking into consideration the two transitions (1)³Π₀₊-(1)³Δ₁ and (1)³Π₀₊ -X³Σ₀₊. The calculation of the Franck-Condon factors, the radiative lifetimes, the total branching ratio, the slowing distance, and the laser cooling scheme study prove that the molecule LuF is a good candidate for Doppler laser cooling.

Ab-initio study of the electronic structure of LaF including spin-orbit coupling

Spectroscopic investigation of lanthanum monofluoride molecule LaF is carried out by ab-initio methods and all the observed band systems are predicted through the fine structure of LaH. This structure consisted of 67 Ω^(±) states is calculated by taking into account the spin-orbit coupling effect of lanthanum. Therefore, these Ω^(±) states are degenerated from 33 low-lying ^1,3Λ^(±) states below 33,200 cm^-1. The potential energy curves (PECs) of ^1,3Λ^(±) and Ω^(±) states are displayed in the range of internuclear distance from 1.40 to 3.00 Å and their spectroscopic constants ([Formula: see text],[Formula: see text], [Formula: see text], [Formula: see text]) are reported. Moreover, the permanent and the transition dipole moments are plotted as a function of internuclear distance. Furthermore, the composition of the Ω^(±) state-wave functions in terms of Λ-S parent states is calculated at the equilibrium internuclear distance of the ground state. Furthermore, through calculating the splitting energy between the spin-orbit components of a ³Λ^(±) state, Hund's case of many states involved in the observed band systems is determined.

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

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 (PEC_s in a range of internuclear distance R varying from 2.00 to 4.22 Å. Graphical AbstractPotential energy curves for 13 singlet electronic states of LaBr.

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

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 ^2S+ 1 Λ^(±) electronic states located below 24,000 cm^- 1 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.

Theoretical investigation of the lowest-lying electronic structure of LuI molecules

CASSCF/MRCI calculations using Effective Core Potential (ECP) basis sets for both Lu and I atoms, have been performed for the first 22 electronic states in the representation (2s+1)Λ((±)) for the LuI molecule. This investigation included the corresponding 43 molecular states in the representation Ω((±)) when taking the spin-orbit coupling (SOC) in consideration. Calculated potential energy curves (PECs) have been displayed. Spectroscopic constants T(e), ω(e), ω(e)χ(e), B(e) and the internuclear distance R(e) have been calculated for the ground state and for the low-lying electronic states situated below 40,410 cm(-1) and for their corresponding components with SOC. The transition dipolar moments between states have been given at the minimum position R(e)=2.75 Å of the ground state X(1)Σ(+). The calculated set of singlet and triplet states provides a theoretical prediction for more than 19 yet unobserved electronic states.