where Ĥ0 , ĤZ and Ŵ are free-particle Hamiltonian, electron nucleus attraction potential and inter-electronic repulsion potentials respectively. ĤH = Ĥ0 + ĤZ is the sum of Hamiltonians of a Hydrogenic atom with Z. Consequently, the density matrix corresponding to ĤH produces von Weizsäcker kinetic energy with correction which can be computed in a systematic manner .