Electronic structure study of the high-pressure vibrational spectrum of FeS2 pyrite.
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.
Blanchard
Marc
M
Royal Institution of Great Britain, 21 Albemarle Street, London W1S 4BS, UK. marc@ri.ac.uk
Alfredsson
Maria
M
Brodholt
John
J
Price
G David
GD
Wright
Kate
K
Catlow
C Richard A
CR