Momentum space properties from coordinate space electron density
  Electron density and electron momentum density, while independently tractable experimentally, bear no direct connection without going through the many-electron wave function. However, invoking a variant of the constrained-search formulation of density functional theory, we develop a general scheme (valid for arbitrary external potentials) yielding decent momentum space properties, starting exclusively from the coordinate space electron density. Numerical illustration of the scheme is provided for the closed-shell atomic systems He, Be and Ne and for $1s^1~2s^1$ singlet electronic excited state for Helium by calculating the Compton profiles and the $<p^n>$ expectation values derived from given coordinate space electron densities. 
M. K. Harbola (1), Rajendra R. Zope (2), Anjali Kshirsagar (3), and   Rajeev K. Pathak (3) ((1) Indian Institute of Technolo...