High-order symplectic integration: an assessment

We report tests of some new symplectic integration routines of sixth and ei ghth order applied to the integration of classical trajectories for a triat omic model molecule. This system has mixed regular and chaotic phase space. Especially for long-lived trajectories, which are trapped in the stochasti c layers of the phase space, the eighth-order integrators are very powerful . Among a great number of integrating routines tested by the authors they a re the most efficient ones, i.e. they need the smallest computational expen se at a prescribed accuracy level. (C) 2000 Elsevier Science B.V. All right s reserved.