Quantum defect theory

Abstract

Quantum defect theory (QDT) is concerned with the properties of an electron in the field of a positive ion and, in particular, with expressing those properties in terms of analytical functions of the energy. It provides a unified theory of bound states, including series perturbations, autoionisation and electron-ion scattering, both elastic and inelastic.The main emphasis of the review is on the foundations of the theory. Properties of Coulomb functions are discussed in some detail and outline sketches are given of relevant topics in collision theory and radiative theory. One-channel and manychannel QDT are discussed separately. Applications to the following problems are considered: resonances, atomic collision calculations, systems with two energy levels of the ion core, helium, other rare gases, alkaline earths and other atomic systems, molecular hydrogen, dielectronic recombination.

Optimization of generalized multichannel quantum defect reference functions for Feshbach resonance characterization

“…As implemented in ref. [1], the scattering matrix S is obtained by applying the relevant asymptotic conditions to first extract the open block of the reaction matrix K defined by: The S matrix is then restricted by definition to the open channels:…”

Reactive collisions of electrons with H2+, HD+, BeH+, BeD+ and SH+

“…In order to obtain a detailed approach of the indirect mechanism and of the vibronic couplings between the ionization channels we used a method based on the multichannel quantum defect theory (MQDT) [4,5], presented in more in details in Refs. [6,7].…”

High‐resolution Photoelectron Spectroscopy

“…(Adapted from Maeda et al (1993)) ground state leads to the excitation of five channels developed by Seaton to describe atomic spectra (Seaton 1983), has been extended to the treatment of molecular spectra and has been reviewed in the book edited by Jungen (1996) and is presented in Chapter HRS024 of this handbook.…”