Date of Original Version
The present paper clarifies a number of issues concerning the general problem of constructing improved short time quantum mechanical propagators. Cumulant methods are shown to be a particularly convenient tool for this task. Numerical results comparing methods based on partial averaging and on gradient approaches are presented for simple model problems and for many particle quantum fluids.
R.D. Coalson, D.L. Freeman and J.D. Doll, “Cumulant Methods and Short Time Propagators,” Journal of Chemical Physics, 91, 4242 (1989).