Recent progress in semiclassical wavepacket methods for chemical physics applications

The position–momentum correlation for quantum and classical probability distributions

“…The position-momentum correlation is a statistical property that is defined for classical phasespace distributions as well as for quantum mechanical wave packets [1][2][3][4]. In both cases, this quantity is responsible for a possible spreading or shrinking of the associated position distribution (see for instance [3,5]). In classical statistical mechanics, the correlation of position and momentum can be easily pictured by means of the joint probability density.…”