Ab initio lattice stabilities of some elemental complex structures

Abstract

The enthalpies of a large number of elements at zero Kelvin in a variety of structures have been computed using electronic density functional theory. The structural enthalpy differences at zero temperature, i.e. lattice stabilities, among the face-centered-cubic (fcc, A1), body-centered-cubic (bcc, A2), α -Mn-type ( χ , A12), and β -Mn-type (A13), and several Frank–Kasper crystal structures, such as Cr 3Si-type (A15), MgZn 2-type (C14), MgCu 2-type (C15), FeCr-type ( σ , D 8 b ), Fe 7W 6-type ( μ ), Mn 5Si 2-type, and Zr 4Al 3-type, are evaluated and examined. The structures are critically examined after structural relaxation to verify that local coordination numbers have been preserved using heuristic methods. In many cases, relaxations change coordination shells and topologies, especially for the non-metals and semimetals in columns IV, V, and VI of the periodic table. Where possible, lattice stabilities have been compared with other ab initio computed lattice stabilities and with enthalpy data in the Scientific Group Thermodata Europe (SGTE) database.