title: Experimental and theoretical investigation on the relative stability of the PdS2- and pyrite-type structures of PdSe2.
abstract: Under ambient condition PdSe2 has the PdS2-type structure. The crystal structure of PdSe2 under pressure (up to 30 GPa) was investigated at room temperature by X-ray diffraction in an energy-dispersive configuration using a diamond anvil cell with a mixture of water/ethanol/methanol as a pressure transmitting medium. A reversible structural transition from the PdS2-type to the pyrite-type structure occurs around 10 GPa, and the applied pressure reduces the spacing between adjacent 2/proportional to [PdSe2] layers of the PdS2-type structure to form the three-dimensional lattice of the pyrite-type structure. First principles and extended Hückel electronic band structure calculations were carried out to confirm the observed pressure-induced structural changes. We also examined why the isoelectronic analogues NiSe2 and PtSe2 adopt structures different from the PdS2-type structure on the basis of qualitative electronic structure considerations.
authors.affiliation: Laboratoire de Chimie des Solides (UMR 6502), Institut des Matériaux Jean Rouxel, 2 Rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3, France.
authors.forename: C
authors.initials: C
authors.lastname: Soulard
authors.forename: X
authors.initials: X
authors.lastname: Rocquefelte
authors.forename: P-E
authors.initials: PE
authors.lastname: Petit
authors.forename: M
authors.initials: M
authors.lastname: Evain
authors.forename: S
authors.initials: S
authors.lastname: Jobic
authors.forename: J-P
authors.initials: JP
authors.lastname: Itié
authors.forename: P
authors.initials: P
authors.lastname: Munsch
authors.forename: H-J
authors.initials: HJ
authors.lastname: Koo
authors.forename: M-H
authors.initials: MH
authors.lastname: Whangbo