Dense low-coordination phases of lithium.
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.
Pickard
Chris J
CJ
Scottish Universities Physics Alliance, School of Physics and Astronomy, University of St. Andrews, St Andrews, KY16 9SS, United Kingdom.
Needs
R J
RJ