Pressure dependence of HgSe elastic properties:: Ultrasound propagation, X-ray diffraction measurements and ab initio calculations

From the measurements of ultrasonic wave velocities in HgSe monocrystals at hydrostatic pressures up to 0.35 GPa the pressure dependence of the second order elastic constants, the value of bulk modulus, and its pressure derivative were determined at room temperature. The parameters describing the HgSe equation of state were estimated independently from high-pressure powder X-ray diffraction studies performed using a cubic-anvil press and synchrotron radiation. Elastic constant and bulk modulus values were also obtained from first-principle calculations performed within the local density approximation (LDA) using pseudopotentials and the mixed-basis method. Our results are compared to the literature data.