Equation of state and metallization of neon

Abstract

The linear combination of Gaussian-type orbitals technique is used to study the bulk properties, equation of state, and metallization pressure of Ne using the Kohn-Sham-Gaspar local-density approximation to density-functional theory. Unlike previous non-muffin-tin calculations for Ne, the present results are obtained for enough values of the lattice parameter to allow a careful determination of the equilibrium lattice constant, binding energy, and bulk modulus. Although the properties of Ne for pressures up to about 3 Mbar are in qualitative agreement with prior results, there are quantitative differences. In particular, as has been found in Li and Fe, the non-muffin-tin lattice constant is contracted relative to the muffin-tin result. The metallization pressure of Ne is determined to be 1.34 Gbar at a lattice constant of 2.32 a.u. as opposed to an earlier augmented plane wave prediction of 1.58 Gbar at 2.256 a.u. An explanation is given for what has been referred to as the ‘‘anomalously’’ large metallization pressure of Ne.