Electron-atom scattering resonances: Complex-scaled multiconfigurational spin-tensor electron propagator method forB−shaperesonances

Abstract

We develop the complex-scaled multiconfigurational spin-tensor electron propagator (CMCSTEP) technique for the theoretical determination of resonance parameters with electron-atom--molecule systems including open-shell and highly correlated (nondynamical correlation) atoms and molecules. The multiconfigurational spin-tensor electron propagator method developed and implemented by Yeager and his coworkers in real space gives very accurate and reliable ionization potentials and electron affinities. The CMCSTEP method uses a complex-scaled multiconfigurational self-consistent field state as an initial state along with a dilated Hamiltonian where all of the electronic coordinates are scaled by a complex factor. We apply the CMCSTEP and the related ${\text{M}}_{1}$ methods to get the ${\text{B}}^{\ensuremath{-}}$ shape resonance parameters using $14s11p$ and $14s11p5d$ basis sets with $1s2s2p3s$, $1s2s2p3s3p$, $1s2s2p3d$, $2s2p3s3p$, $2s2p3d$, and $2s2p3s3p3d$ complete active spaces. The CMCSTEP and ${\text{M}}_{1}$ resonance positions and widths are obtained for the $1{s}^{2}2{s}^{2}2{p}^{2}{\phantom{\rule{0.16em}{0ex}}}^{1}D$, $1{s}^{2}2s2{p}^{3}{\phantom{\rule{0.16em}{0ex}}}^{3}D$, and $1s2{s}^{2}2{p}^{3}{\phantom{\rule{0.16em}{0ex}}}^{3}D$, ${}^{3}S$, and ${}^{3}P$ shape resonances.