Atomic photoionization by the complex-basis-function expansion method: Application to ground-state and metastable Mg

We present photoionization cross sections for the ground and metastable (3s3p)³P states of atomic magnesium, using ab initio many-electron wave functions in the LS-coupling scheme. The effects of initial-state correlation and channel coupling are incorporated in a straightforward manner with use of configuration-interaction methods. The selective use of complex basis functions obviates the need for explicit construction of continuum wave functions. This method also provides a convenient way of incorporating the effects of autoionization into atomic photoionization cross sections.