Magnetoelasticity of Fe: Possible failure of <i>ab initio</i> electron theory with the local-spin-density approximation and with the generalized-gradient approximation

M. Fähnle; M. Komelj; R. Q. Wu; G. Y. Guo

doi:10.1103/PhysRevB.65.144436

Magnetoelasticity of Fe: Possible failure of ab initio electron theory with the local-spin-density approximation and with the generalized-gradient approximation

M. Fähnle, M. Komelj, R. Q. Wu, and G. Y. Guo

Phys. Rev. B 65, 144436 – Published 2 April 2002

Abstract

The magnetoelastic coupling constant $B_{2}$ and the related magnetostriction coefficient $λ_{111}$ of bcc Fe are calculated by the ab initio density functional electron theory in local-spin-density approximation and in generalized-gradient approximation. Both $B_{2}$ and $λ_{111}$ exhibit a wrong sign as compared to the available experimental data, indicating a possible deficiency of the two approximations for the exchange-correlation functional.