Theoretical complex Stark energies of hydrogen by a complex-scaling plus<i>B</i>-spline approach

Abstract

The complex-scaled (r\ensuremath{\rightarrow}${\mathit{re}}^{\mathit{i}\mathrm{\ensuremath{\theta}}}$) Stark Hamiltonian of hydrogen is diagonalized with a B-spline basis. Accurate complex energies of low-lying resonances are obtained for a wide range of electric-field strength (from 0.03 to 2.0 a.u.). The high accuracy is attributed to the good stationarity behavior of \ensuremath{\theta} trajectories with a well-adjusted B-spline basis.