title: High-pressure study of binary thorium compounds from first principles theory and comparisons with experiment.
abstract: The high-pressure structural behaviour of a series of binary thorium compounds ThX (X = C, N, P, As, Sb, Bi, S, Se, Te) is studied using the all-electron full potential linear muffin-tin orbital (FP-LMTO) method within the generalized gradient approximation (GGA) for the exchange and correlation potential. The calculated equlibrium lattice parameters and bulk moduli, as well as the equations of state agree well with experimental results. New experiments are reported for ThBi and ThN. Calculations are performed for the ThX compounds in the NaCl- and CsCl-type crystal structures, and structural phase transitions from NaCl to CsCl are found in ThP, ThAs, ThSb and ThSe at pressures of 26.1, 22.1, 8.1 and 23.2 GPa, respectively, in excellent agreement with experimental results. ThC, ThN and ThS are found to be stable in the NaCl structure, and ThBi and ThTe in the CsCl structure, for pressures below 50 GPa. The electronic structures of the ThX compounds are studied using the quasiparticle self-consistent GW method (G: Green function, W: dynamically screened interaction).
authors.affiliation: Department of Physics, Indian Institute of Technology Hyderabad, Ordnance Factory Estate, Yeddumailaram 502 205, Andhra Pradesh, India.
authors.forename: V
authors.initials: V
authors.lastname: Kanchana
authors.affiliation: Advanced Centre of Research in High Energy Materials (ACRHEM), University of Hyderabad, Prof. C. R. Rao Road, Gachibowli, Andhra Pradesh, Hyderabad 500 046, India.
authors.forename: G
authors.initials: G
authors.lastname: Vaitheeswaran
authors.affiliation: Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus-C, Denmark.
authors.forename: A
authors.initials: A
authors.lastname: Svane
authors.affiliation: European Commission, Joint Research Centre, Institute for Transuranium Elements, Postfach 2340, D-76125 Karlsruhe, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Heathman
authors.affiliation: Department of Physics, Technical University of Denmark, DK-2800 Lyngby, Denmark.
authors.forename: L
authors.initials: L
authors.lastname: Gerward
authors.affiliation: Niels Bohr Institute, Ørsted Laboratory, DK-2100 Copenhagen, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Staun Olsen
keywords: ceramics; first principles theory; generalized gradient approximation; high pressure