Pranaav singh On Quantum classical correspondence of Dirac equation. (Revised) (266K, .pdf) ABSTRACT. The unphysical results of quantum classical correspondence of Dirac equation have been analyzed. To evaluate observables in Dirac s theory of electron, a new prescription has been put forward that completely eliminates unphysical phenomena such as zitterbewegung. Spin angular momentum of free, non relativistic electron has been found questionable. Ultra relativistic behavior of electron has been studied for remarkable consequences like apparent masslessness and luminal propagation.