The first principles calculation of transport coefficients

TL;DR

This paper demonstrates how to calculate transport coefficients like viscosity from first principles using Green-Kubo relations, with applications to liquid metals and Earth's core conditions.

Contribution

It shows the feasibility of first-principles calculations of transport properties with low statistical error, including for complex alloys under extreme conditions.

Findings

Viscosity of liquid aluminum calculated with ca. 5% error.

Liquid iron-sulfur alloy viscosity under Earth's core conditions.

Outer core liquid viscosity not much higher than ambient liquid metals.

Abstract

We demonstrate the practical feasibility of calculating transport coefficients such as the viscosity of liquids completely from first principles using the Green-Kubo relations. Results presented for liquid aluminum are shown to have a statistical error of only ca. 5%. The importance of such calculations is illustrated by results for a liquid iron-sulfur alloy under Earth's core conditions, which indicate that the viscosity of the liquid outer core is not substantially higher than that of typical liquid metals under ambient conditions.