Vibrational and thermophysical properties of PETN from first principles

• Main Authors: Gonzalez, Joseph M., Landerville, Aaron C., Oleynik, Ivan I.
• Format: Conference Proceeding
• Language: English
• Subjects: Density functional theory; Energetic materials; Equations of state; First principles; Free energy; Mathematical models; Modelling; PETN; Properties (attributes); Thermal expansion; Thermophysical models; Thermophysical properties
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/1.4971597

Thermophysical properties are urgently sought as input for meso- and continuum-scale modeling of energetic materials (EMs). However, experimental data are often limited as they cover a narrow region of specific pressures and temperatures. Such modeling of EMs can be greatly improved by inclusion of thermophysical properties over a wide range of pressures and temperatures, provided such data could be reliably obtained from theory. We demonstrate such a capability by calculating the PVT equation of state, heat capacities, and coefficients of thermal expansion for pentaerythritol tetranitrate (PETN) using first-principles density functional theory, which includes proper description of van der Waals interactions, zero-point energy and thermal contributions to free energy calculated using the quasi-harmonic approximation. Further, we investigate the evolution of the vibration spectrum of PETN as a function of pressure.