ENERGY AND AUTOIONIZATION WIDTH OF THE 1S3S3P4P0 AND 1S3P3P4P STATES IN LITHIUMLIKE IONS

The saddle-point complex-rotation method is used to compute the energies and autoionization widths of the 1s3s3p 4P°and 1s3p3p 4P Feshbach resonances for the lithiumlike ions with nuclear charges from Z=2 to 6. These doubly core-excited quartet states rapidly autoionize, emitting low-energy electrons via the continua associated with the 1s2s 3S and 1s2p 3P°states of the residual ion. The radiative decay rates of these initial states are shown to be small relative to their autoionization rates, so that the lifetimes of these resonances are essentially determined by their widths due to autoionization. A detailed study of the closed-channel component of the 1s3p3p 4P resonance is made in order to investigate the degree to which the saddle-point solution approximates this component of the resonance wave function. © 1990 The American Physical Society.