RECURRENCES WITHOUT CLOSED ORBITS

The results of quantum photoabsorption calculations are presented for H, K, and Cs atoms in static electric fields. The recurrence spectra f or [L-z] not equal 0 show features at scaled actions an order of magni tude shorter than for any classical closed orbit of this system. Two i nteresting manifestations are presented, and some of the systematics o f the peak strengths are explored. These features suggest that closed- orbit theory may need to be generalized to account for these effects. A heuristic formula is presented that reproduces some of these effects . [S1050-2947(98)02108-8]