Large effects of subtle electronic correlations on the energetics of vacancies in alpha-Fe
We study the effect of electronic Coulomb correlations on the vacancy formation energy in paramagnetic alpha-Fe within ab initio dynamical mean-field theory. The calculated value for the formation energy is substantially lower than in standard density-functional calculations and in excellent agreement with experiment. The reduction is caused by an enhancement of electronic correlations at the nearest neighbors of the vacancy. This effect is explained by subtle changes in the corresponding spectral function of the d electrons. The local lattice relaxations around the vacancy are substantially increased by many-body effects. ; Funding Agencies|Ministry of Education and Science of the Russian Federation; Swedish Research Council (VR) [2014-4750]; LiLi-NFM; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009 00971]; FP7/ERC [278472-MottMetals]; IDRIS/GENCI Orsay [t2016091393]; European Research Council under the European Unions Seventh Framework Programme/ERC Grant [617196, 319286]; Increase Competitiveness Program of NUST MISiS [K2-2016-013]