Interpretation of Hugoniot Elastic Limit Experiments Based on High-Pressure Thermoelastic Simulations

Its primary objective is to provide a continuous sound velocity-pressure response relationship for the precise determination of the Hugoniot Elastic Limit (HEL).The theoretically simulated thermoelastic dataset was generated using the following methods: The static energy-volume relationship was obtained via first-principles calculations using the Vienna Ab initio Simulation Package (VASP) and fitted to the fourth-order Birch-Murnaghan Equation of State (EOS).

Building upon this, the diamond EOS covering a wide temperature and pressure range (0–1000 K, 0–500 GPa) was constructed by combining the Quasi-Harmonic Approximation (QHA) with the Mean-Field Potential (MFP) method. Subsequently, elastic constants and sound velocities were derived from the EOS using the energy-strain method within the Quasi-Static Approximation (QSA) framework.The simulation dataset includes the following key physical quantities: temperature (T), pressure (P), elastic constants (C11, C12, C44), bulk moduli (BV, BR, BH) and shear moduli (GV, GR, GH) under the Voigt-Reuss-Hill approximation, Young's modulus (EH), Poisson's ratio (nuH), related moduli (kH, HH), anisotropy indices (AVR, AU), as well as longitudinal sound velocity (CL) and bulk sound velocity (CB).