A NUMERICAL TEST OF DIFFERENT INTEGRAL CONDITIONING APPROXIMATIONS FOR A SEMICLASSICAL INITIAL-VALUE REPRESENTATION FOR WAVEPACKET PROPAGATION

Recent numerical evidence indicates that the rapid spreading of nearby classical trajectories in chaotic regions results in numerical diffic ulties and reduced accuracy for semiclassical initial value representa tion methods. These problems can be significantly reduced and the accu racy of the methods increased through the application of integral cond itioning techniques, which have been developed for the numerical evalu ation of integrals with highly oscillatory integrands. This work studi es the effectiveness of these conditioning techniques, when applied to one semiclassical initial value representation wavepacket propagation procedure, the HK propagator method. (C) 1998 Elsevier Science B.V.