Theoretical study of the alkaline-earth (LiBe)⁺ion: structure, spectroscopy and dipole moments

Abstract

We study theoretically the structure and spectroscopic properties of the alkali alkaline-earth (LiBe) + ion. The potential energy curves and their spectroscopic parameters, permanent and transition dipole moments are determined with a quantum chemistry approach. The (LiBe) + ion is modelled as two valence electron system moving in the field of Be 2+ and Li + cores, which are described by pseudopotentials. In addition, effective core-polarization potentials are included to correct the energy. The molecular calculations are performed using a standard quantum chemistry approach based on the pseudopotential model, Gaussian basis sets, effective core polarization potentials, and full configuration interaction (CI) calculations. The precision of our spectroscopic parameters are discussed by comparison with currently available theoretical results. A rather good agreement is observed for the ground and first excited states. The permanent dipole moments reveal many abrupt changes, which are localized at particular distances corresponding to the positions of the avoided crossings.

Spectroscopic properties of the molecular ions BeX+ (X=Na, K, Rb): forming cold molecular ions from an ion–atom mixture by stimulated Raman adiabatic process

“…As in previous works on LiH [39], LiNa [40] and LiCs [41], the BeX + (X=H and Li) molecular ion [42,43] is treated as a two-valence electron system using the nonempirical pseudopotential of Barthelat and Durand [44], in its semi-local form and used in many previous works [39][40][41][45][46][47][48][49][50][51][52]. Furthermore, the self-consistent field calculation (SCF) is followed by a full valence configuration interaction (FCI) calculation using the CIPCI algorithm of the standard chain of programs of the Laboratoire de Physique Quantique of Toulouse.…”

“…It has a physical meaning of excluding the valence electrons from the core region for calculating the electric field. For the Beryllium, Sodium, Potassium and Rubidium atoms, we used (7s9p10d/7s8p9d) [42,43], (7s6p5d3f/6s5p4d2f) [55], (7s5p7d1f/6s5p5d1f) [56] and (7s4p5d1f/6s4p4d1f) [57], basis set of Gaussian-type orbital, where diffuse orbital exponents have been optimized to reproduce the atomic states 2s, 2p, 3s, 3p and 3d, and 2s 2 , 2s2p, 2s3s, 2p 2 , 2s3p and 2s3d for Be + and Be species, respectively. Following the formulation of Foucrault et al .…”

Cold hybrid ion-atom systems

“…where the expressions in round brackets are 3j symbols, 2S+1 L||Q 2(4) || 2S+1 L is the reduced matrix element of the quadrupole (hexadecapole) moment, and α 0 (iω) and α 2 (iω) are the scalar and tensor components of the dynamic electric dipole polarizability at imaginary frequency of the atom in the 2S+1 L state. The electronic structure data, including the potential energy curves for the ground and excited electronic states, transition electric dipole moments, and matrix elements of the spin-orbit coupling have been calculated for several ion-atom systems relevant for ongoing experimental efforts: (Na+Ca) + (Gacesa et al, 2016;Makarov et al, 2003), (Rb+Ba) + (Knecht et al, 2010;Krych et al, 2011), (Li/Na/K/Rb/Cs+Sr) + , (Rb+Ca) + (Belyaev et al, 2012;Tacconi et al, 2011), (Rb+Yb) + (Lamb et al, 2012;McLaughlin et al, 2014;Sayfutyarova et al, 2013), (Li+Yb) + da Silva Jr et al, 2015;Tomza et al, 2015), (Ca/Sr/Ba/Yb+Cr) + (Tomza, 2015), (Li+Be) + (Ghanmi et al, 2017), (Li+Mg) + (ElOualhazi and , (Li+Ca) + (Saito et al, 2017), (Li+Sr) + (Jellali et al, 2016), (Rb+Ca/Sr/Ba/Yb) + (da Silva Jr et al, 2015), (Na/Ka/Rb+Be) + (Ladjimi et al, 2018), (Li+Li) + (Bouchelaghem and Bouledroua, 2014;Bouzouita et al, 2006;Musia l et al, 2015), (Na+Na) + (Berriche, 2013;Bewicz et al, 2017), (K+K) + (Skupin et al, 2017), (Rb+Rb) + (Jraij et al, 2003;Jyothi et al, 2016), (Cs+Cs) + (Jamieson et al, 2009;Jraij et al, 2005), (Li+Na) + (Li et al, 2015;Musia l et al, 2018), (Li+K) + (Berriche et al, 2005;…”

Calculations of electronic properties and vibrational parameters of alkaline-earth lithides: MgLi+ and CaLi+

“…The diatomic molecules containing alkali-alkaline-earthmetals (XY; Y = Li, Na, K, Rb, Cs) have strong longrange interactions owing to their large dipole moments [32,33]. Their spectroscopic constants and molecular properties have been investigated by several research * Electronic address: rbala@ph.iitr.ac.in groups [32,[34][35][36][37]. Both CaLi and SrLi molecules have also been proposed for the study of m p /m e [38].…”