Quantum and classical probability distributions for arbitrary Hamiltonian

In the limit of large quantum excitations, the classical and quantum probability distributions for a Schr"odinger equation can be compared by using the corresponding WKBJ solutions whose rapid oscillations are averaged. This result is extended for one-dimensional Hamiltonians with a non-usual kinetic part. The validity of the approach is tested with a Hamiltonian containing a relativistic kinetic energy operator.