REOS - A PROGRAM FOR RELAXED-ORBITAL OSCILLATOR STRENGTH CALCULATIONS

A spontaneous decay of an excited atomic state leads to a rearrangemen t of the spatial electron distribution in the atom. This redistributio n concerns the entire electronic cloud and not only the active electro n in an atomic transition. For many-electron atoms, rearrangement effe cts are naturally included if the electronic wavefunctions of the init ial and final states are determined independently. The separate optimi zation of the atomic states, however, yields two sets of one-electron orbitals which are not orthogonal to each other. This incomplete ortho gonality also influences the calculation of transition amplitudes sinc e, additionally, many small contributions arise from the radial overla p of electrons of different subshells which have the same symmetry. In the framework of the GRASP92 atomic structure package we describe a p rogram for the computation of oscillator strengths and Einstein A and B coefficients. The program is based on a determinant representation o f the atomic states and allows for incomplete orthogonal radial orbita l functions for the initial and final states. For large Lists of confi guration state functions, this module also facilitates the computation of transition arrays since the initial and final states need not to b e determined in the same nun.