Cubic zirconium tungstate (α‐ZrW2O8), a well‐known negative thermal expansion material, has been investigated within the framework of density functional perturbation theory (DFPT), combined with experimental characterization to assess and validate computational results. Using combined Fourier transform infrared measurements and DFPT calculations, new and extensive assignments were made for the far‐infrared (<400 cm−1) spectrum of α‐ZrW2O8. A systematic comparison of DFPT‐simulated infrared, Raman, and phonon density‐of‐state spectra with Fourier transform far‐/mid‐infrared and Raman data collected in this study, as well as with available inelastic neutron scattering measurements, shows the superior accuracy of the PBEsol exchange‐correlation functional over standard PBE calculations for studying the spectroscopic properties of this material.

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The negative thermal expansion (NTE) material Zr 2 (WO 4 )(PO 4 ) 2 has been investigated for the first time within the framework of the density functional perturbation theory (DFPT). The structural, mechanical, and thermodynamic properties of this material have been predicted using the Perdew, Burke and Ernzerhof for solid (PBEsol) exchange–correlation functional, which showed superior accuracy over standard functionals in previous computational studies of the NTE material α-ZrW 2 O 8 . The bulk modulus calculated for Zr 2 (WO 4 )(PO 4 ) 2 using the Vinet equation of state at room temperature is K 0 = 63.6 GPa, which is in close agreement with the experimental estimate of 61.3(8) at T = 296 K. The computed mean linear coefficient of thermal expansion is −3.1 × 10 –6 K −1 in the temperature range ∼0–70 K, in line with the X-ray diffraction measurements. The mean Grüneisen parameter controlling the thermal expansion of Zr 2 (WO 4 )(PO 4 ) 2 is negative below 205 K, with a minimum of −2.1 at 10 K. The calculated standard molar heat capacity and entropy are C P 0 = 287.6 and S 0 = 321.9 J·mol –1 ·K –1 , respectively. The results reported in this study demonstrate the accuracy of DFPT/PBEsol for assessing or predicting the relationship between structural and thermomechanical properties of NTE materials.

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The cover image, by Philippe F. Weck et al., is based on the Research Article Infrared and Raman spectroscopy of α‐ZrW2O8: A comprehensive density functional perturbation theory and experimental study, https://doi.org/10.1002/jrs.5396.