Molecular polarizability in quantum defect theory: Nonpolar molecules

Abstract

The method of reduced-added Green's function in quantum defect approximation ͓V. E. Chernov, D. L. Dorofeev, I. Yu. Kretinin, and B. A. Zon, Phys. Rev. A 71, 022505 ͑2005͔͒ is generalized for calculation of dynamic polarizabilities of nonpolar molecules. The method is applied to alkali-metal dimers Li 2 , Na 2 , and Rb 2 . The accuracy achieved in benchmark calculation ͑H 2 molecule͒ is comparable to that of ab initio calculations. 1 It was considered for a long time that QDT description is successful only for one electron over complete shells, e.g., for alkalimetal-like atoms and ions. After an error in earlier QDT has been corrected in Ref. ͓14͔, the modified QDT is capable to treat optical electron states in any complex atom. The wave function of such a state is determined by the QDs of the whole spectral series ͑not only by the QD of the given state͒.

Molecular polarizability in quantum defect theory: polar molecules

“…Equation (19) differs from the corresponding expression for nonpolar molecules [2] by the dependence on dipole moment via the noninteger quasimomentum lm . By the similar way we introduce the function,…”

“…The dynamic polarizabilities of homonuclear alkali-metal dimers, which were among the first cold molecules produced experimentally, was calculated in the previous paper [2]. In this context there is growing interest in electronic properties of polar alkali-metal hydrides, LiH and NaH [5,6], whose polarizabilities are presented in this paper.…”

“…The previous papers of the present series discussed the modifications of the quantum defect theory (QDT) which allowed us to use it for calculation of frequency-dependent (dynamic) polarizabilities of different (close-and open-shell) atoms [1] and nonpolar diatomic molecules [2]. In the present paper we develop the theory further to calculate the dynamic polarizabilities of polar diatomic molecules.…”

“…In the present paper we give the further development of the quantum defect Green's function (QDGF) technique [1,2] and generalize it for calculation of polarizabilities of polar molecules. This technique combines the ab initio description of the ground and low-excited molecular states with the analytical description of the high-excited and continuum states of the optical electron in polar molecules using the dipolespherical functions as exact solutions for the Schrödinger equation with dipole-Coulomb potential.…”

Interesting periodic variations in physical and chemical properties of homonuclear diatomic molecules

“…[54]: using MP2 (experimental values are given in bracket); Ref. [46]: using QDFG (Greens function formalism in quantum defect theory); Ref. [45]: using TDDFT within ALDA; Ref.…”