Structural characterization of slightly boron-deficient LiB, LiB0.9 and LiB0.8, under pressure

Results of computational investigations of two slightly boron-deficient lithium borides, LiB0.9 and LiB0.8, under pressure are reported. Structure predictions based on particle swarm optimization reveal that at low pressure both compositions adopt chain structures, as stoichiometric 1 : 1 LiB. With increasing pressure both undergo phase transitions to layered arrangements. The evolution of the structural parameters of these stoichiometries as a function of pressure and the results obtained from the enthalpies indicate that boron-deficient structures are more favoured than 1 : 1 LiB, even at zero pressure. Moreover, as pressure is increased a larger deficiency in B seems to be favoured.A Bergara, I G Gurtubay and A Suarez-Alcubilla are grateful to the Department of Education, Universities and Research of the Basque Government, UPV/EHU (Grant No. IT756-13) and the Spanish Ministry of Economy and Competitiveness MINECO (Grants No. FIS2013-48286-C2-1-P and FIS2013-48286-C2-2-P) for financial support. A Suarez-Alcubilla also acknowledges support from the CSIC-JaePredoc program, co-financed by ESF.Peer Reviewe