Improved predictions of thermomechanical properties of molecular crystals from energy and dispersion corrected DFT

Thermal stability and pressure-dependent changes are key to molecular crystals their properties. The determination of thermal properties from ab initio methods is, however, a challenging task. While the low-frequency phonon spectrum related intermolecular vibrations remains difficult describe, Quasi-Harmonic Approximation (QHA) also induces for significant volume deviation, which makes behavior ill-determined. To overcome these difficulties, we consider pragmatic energy correction (EC) that has long been used atomic crystals, presently report first ever use crystals. Applying QHA in dispersion-corrected density functional theory (DFT-D) calculations with an parameterized EC, resulting model can simultaneously accurately derive mechanical high-explosive When compared experiments, mean absolute percent error previous DFT-based thermomechanical models is 12% 31% Our performs significantly better reduces uncertainties 4.1% 9.8%, respectively. In particular, agreement between our experiments three times better. This improvement greatly benefits such as Grüneisen parameter shock method successfully applied showing large diversity weak interactions (β-1,3,5,7-tetranitro-1,3,5,7-tetrazoctane (HMX), α-1,1-diamino-2,2-dinitroethylene (FOX-7), Triaminotrinitrobenzene (TATB), ε-Hexanitrohexaazaisowurtzitane (CL20), Pentaerythritol tetranitrate (PETN)-I). Due its accuracy transferability, expected work class computationally designed co-crystals, providing basis predictive framework.