Proposal for extraction of the exchange correlation potential of DFT from X-ray scattering measurements on the 'almost spherical' inhomogeneous electron liquids in CH4 and NH4+

摘要

Experimental X-ray scattering data exists oil the inhomogeneous electron liquids ill the almost spherical 10-electron systems CH4 and NH4+. Furthermore, simple but realistic models are available which accurately represent the X-ray data. These are here utilised to construct a route to estimate the force -partial derivative V(r)/partial derivative r where V(r) is the one-body potential of DFT. The total number of electrons, Q(r) say, inside a sphere of radius r around the central atom, C or N, is the essential input from the X-ray data. Quantum chemical calculations can then be used to divide the total ground-state density into s and p contributions. Using the general theory available for 10-electron central field systems, a proposal for extracting the exchange correlation force -partial derivative V-cx/partial derivative r from X-ray data for both CH4 and NH4+ is put forward, V-xc being the exchange correlation potential of DFT.