Dear Prof. Mshelia,

                                  The essential moment in any wave function is its mean which generates the meanfield actions. The Lagrangean Dynamics with its velocity equations over time and states can adequately describe the meanfield dynamics even disaggregated into potentials and kinetics for e.g.. Please refer to Mallick, Hamburger and Mallick (2016) P Vs. NP problem solution on Soumitra K Mallick's RG page for reference.

SKM for SKM,NH,SM (also on Facebook)

Follow the advice of Robert J. Low

The link given by Robert J. Low indeed provides the answer.

If you want a bit more extensive explanation, see, e.g., Chapter 11 in H. Goldstein, Classical Mechanics (1st ed.). Addison-wesley. 1951. There are also newer editions of this book.

Thanks to all for the answers, particularly that by Robert J. Low