title: Dense low-coordination phases of lithium.
abstract: Ab initio density-functional-theory calculations and a structure-searching technique are used to identify candidate high-pressure phases of lithium (Li). We predict threefold coordinated structures to be stable in the pressure range 40-450 GPa and fourfold structures at higher pressures. We describe these low-coordination phases as elemental electrides. All of the stable phases are metallic but the Cmca-24 structure, and two distortions of it which are marginally the most stable in the pressure range 86-106 GPa, are nearly semiconducting with densities of electronic states at the Fermi energy of only a few percent of the free-electron value.
authors.affiliation: Scottish Universities Physics Alliance, School of Physics and Astronomy, University of St. Andrews, St Andrews, KY16 9SS, United Kingdom.
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Pickard
authors.forename: R J
authors.initials: RJ
authors.lastname: Needs