Complex coordinate calculations on autoionizing states of HeH and H2

Complex coordinate-scaling calculations have been carried out on the first three autoionizing 2Σ+ states of HeH and the lowest 1Σ+g(σu2) state of H2, with the aid of a version of the MRDCI program which employs complex-rotated Gaussian-type functions. It has been found that for optimum convergence and stabilization only the basis functions describing the outer electron need to be complex-rotated. The calculated widths are in good agreement with previous calculations on these systems. The present work is the first large-scale application of complex coordinate scaling in conjunction with ab initio configuration interaction methods to molecular autoionizing states.