DENSITY-FUNCTIONAL THEORY OF WIGNER CRYSTALLIZATION

We present a theory of the transition from a low-density electron crystal to a uniform electron gas based on the density-functional formalism. We find a first-order transition near rs=26; for rs slightly greater than the transition value the electrons must still be regarded as itinerant, but with inhomogeneous density. As a step in our calculation we find a new value for the low-density limit of the exchange-correlation energy to replace Wigner's well-known form. © 1978 The American Physical Society.