title: Electronic structure study of the high-pressure vibrational spectrum of FeS2 pyrite.
abstract: Plane-wave density functional calculations are used to investigate the pressure dependence of the geometry and Gamma-point phonons of FeS(2) pyrite up to 150 GPa. The linear response method is employed to calculate the vibrational properties. Raman-active modes are in excellent agreement with the experimental data available up to 50 GPa,(1) and we predict the evolution with pressure of the IR-active modes for which no high-pressure spectroscopic data have been reported so far. Over the wide pressure range investigated here, all vibrational frequencies depend nonlinearly on pressure; their pressure dependence is quantified by determining the full set of mode Grüneisen parameters and their pressure derivatives.
authors.affiliation: Royal Institution of Great Britain, 21 Albemarle Street, London W1S 4BS, UK. marc@ri.ac.uk
authors.forename: Marc
authors.initials: M
authors.lastname: Blanchard
authors.forename: Maria
authors.initials: M
authors.lastname: Alfredsson
authors.forename: John
authors.initials: J
authors.lastname: Brodholt
authors.forename: G David
authors.initials: GD
authors.lastname: Price
authors.forename: Kate
authors.initials: K
authors.lastname: Wright
authors.forename: C Richard A
authors.initials: CR
authors.lastname: Catlow