Yang, W, *Ab initio approach for many-electron systems without invoking orbitals: An integral formulation of density-functional theory*,
Physical Review Letters, vol. 59 no. 14
(1987),
pp. 1569-1572 [doi] .
**Abstract:**

*A new approach for the calculation of ground states of many-electron systems is developed via an integral formulation of the Hohenberg-Kohn-Sham density-functional theory. Orbitals are not employed. In place of the set of one-electron equations, the total electron density is explicitly expressed in terms of the Kohn-Sham local potential through a multidimensional integration. This offers the possibility of ab initio calculations for molecules with very many electrons. The method can also be applied to calculate Compton profiles. © 1987 The American Physical Society.*