On the computations of interatomic Coulombic decay widths with R-matrix method

Abstract

Interatomic Coulombic Decay (ICD) is a general mechanism in which an excited atom can transfer its excess energy to a neighbor which is thus ionized. ICD belongs to the family of Feshbach resonance processes, and, as such, states undergoing ICD are characterized by their energy width. In this work, we investigate the computations of ICD widths using the R-matrix method as implemented in the UKRmol package. Helium dimer is used here as a benchmark system. The results are compared with those obtained with the well established Fano-Algebraic Diagrammatic Construction method. It is shown that the R-matrix method in its present implementation provides accurate total and partial widths if the kinetic energy of the ICD electron is lower than 10 eV. Advantages and limitations of the R-matrix method on the computations of ICD widths are discussed.

Interatomic Coulombic electron capture from first principles

“…The calculations on Ne + -He and Ne + -He 2 in this work were performed using the same parameters as those reported in [15]: we used the cc-pVDZ basis set and the Hartree-Fock (HF) orbitals optimized for the neutral clusters using the MOLPRO package [16,17]. The Rmatrix radius was fixed at 13 a.u.…”

Nonadiabatic dynamics in multidimensional complex potential energy surfaces

“…Alternatively, one could use adapted quantum chemistry methods that directly provide information about the widths. 14,58,59 As one nal potential application of the methodology, we put forward the idea that it could be employed to incorporate the possibility of radiative decay into nonadiabatic dynamics of excited states. Although there are available computational codes for mixed quantum-classical dynamics that place internal conversion and intersystem crossing on an equal footing, 60 we are not aware of implementations that also account for decay by uorescence.…”

Nonadiabatic Dynamics in Multidimensional Complex Potential Energy Surfaces

“…Alterna-tively, one could use adapted quantum chemistry methods that directly provide information about the widths. 14,58,59 As one final potential application of the methodology, we put forward the idea that it could be employed to incorporate the possibility of radiative decay into nonadiabatic dynamics of excited states. Although there are available computational codes for mixed quantum-classical dynamics that place internal conversion and intersystem crossing on an equal footing, 60 we are not aware of implementations that also account for decay by fluorescence.…”