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The structural and electronic properties of (SrLi)+molecular ion have been determined by the use ofab initioapproaches. Potential energy curves (PECs) with their spectroscopic constants (Re,De, ωe,Te,Beand ωeχe) have been calculated. Also, the vibrational properties and the electric dipole moments, either permanent (PDM) or transition (TDM) ones, have been investigated and analysed. Large Gaussian basis sets, the full valence configuration interaction (FCI) and the formalism of non-empirical pseudo-potential including the two approaches, effective core potential (ECP) and core polarisation potential (CPP), are analysed. Therefore, (SrLi)+is considered as a two effective electrons system. Numerous excited states of symmetries1,3Σ+,1,3Π and1,3Δ dissociating below the ionic limit Sr2+Li−have been investigated. This study shows interesting behaviours around the avoided crossing related to charge transfer involving important processes in physics and astrophysics such as dynamics, pre-dissociation and inelastic transitions. [ABSTRACT FROM AUTHOR]

Adiabatic potential energy, spectroscopic constants, dipole moments, and vibrational levels have been computed for the lowest electronic states of alkali dimers LiX and NaX (X = Rb, Cs). Calculations have been carried with the use of an ab initio approach with core‐potential potentials and full‐valence configuration. Thus, these systems are treated as two‐electron systems. A good agreement is obtained for some lowest states of the molecules studied with available theoretical works. The existence of numerous avoided crossings between electronic states for 1Σ symmetries is related to the charge‐transfer process in each molecule between its two ionic systems (Li+X−, Li−X+) and (Na+X−, Na−X+). © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011 [ABSTRACT FROM AUTHOR]

Abstract: For all states dissociating below the ionic limit Li−K+, we perform an adiabatic and diabatic study for electronic states dissociating into K (4s, 4p, 4d, 5s, 5p, 5d, 6s)+Li (2s, 2p, 3s). Furthermore, we present the adiabatic results for the 1–11 , 1–8 and 1–4 states. The present calculations on the KLi molecule are complementary to previous theoretical work on this system, including recently observed electronic states that had not been calculated previously. The calculations rely on an ab initio pseudo-potential, Core Polarization Potential operators for the core–valence correlation and full valence CI approaches, combined to an efficient diabatization procedure. For the low-lying states, our spectroscopic constants and vibrational level spacing are in good agreement with the available experimental data. Diabatic potentials and permanent dipole moments are analyzed, revealing the strong imprint of the ionic state in the adiabatic states. [Copyright &y& Elsevier]

Abstract: The structural and electronic properties of Co4Si4− x Ge x (x=0–4) compounds are investigated using density functional theory (DFT). The calculations are based on a plane-wave expansion of the electronic wave functions using pseudo-potential method and performed using the local density approximation (LDA). It is found that these compounds are semimetals with a slight overlap between valence and conduction bands. The tendency towards metallic behavior of the compounds increases in terms of Ge concentration. [Copyright &y& Elsevier]

• Spectroscopic investigation is carried out in the adiabatic representations (PECs, PDM, TDM). • Illustration of the ionic character and the strong couplings between the excited states. • Spectroscopic parameters and vibrational level spacings are obtained by resolving the radial Schrodinger equation. A non-relativistic description of the electronic structure for the heteronuclear molecule KRb was developed through the Full Configuration Interaction (FCI) and pseudo-potential method. Below the ionic limit K−Rb+, the ground and all excited singlet and triplet states of different symmetries Σ+, Π and Δ (in the Hund's case (a): 2 s + 1Λ±) were intensively investigated. Several adiabatic results including potential energy curves (PECs), permanent and transition electric dipole moments (PEDM, TEDM) were analyzed in short and long-range of internuclear distances. Tables of these properties as functions of separation are presented. The spectroscopic constants with the vibrational levels were derived using the "Numerov" algorithm. These molecular parameters were compared with those published in the literature, feature a good agreement. In the adiabatic representation, strong couplings between successive 1Σ+ states were reached by series of avoided crossing, yielding to the appearance of the ionic character and the good illustration of charge transfer. This description of the KRb molecule was helpful in the design of the prospect photo-association experiments and the obtaining of the quantum-degenerate gas of the polar molecule. [Display omitted] [ABSTRACT FROM AUTHOR]