Modeling Solid-Solid Phase Transitions in PETN Using Density Functional Theory
Abstract
We present density functional theory (DFT) calculations of a stable orthorhombic phase of hydrostatically compressed pen-taerythritol tetranitrate (PETN). In these calculations, an orthorhombic (a not equal b not equal c) structure optimized at a very high pressure was used to initialize crystal structure optimizations at progressively lower pressures until the optimization spontaneously reverted to a tetragonal phase (a = b not equal c). The orthorhombic crystal structures exhibit P2(1)2(1)2 symmetry and a lowering of molecular symmetry from S4 to C2, which matches the orthorhombic PETN III phase debated in the literature. These findings are consistent across several DFT methods; however, the predicted transition pressures range from 16 to 23 GPa depending on the type of the functional and the size of the periodic supercell.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 03, 2018
- Accession Number
- AD1101614
Entities
People
- Igor V Schweigert
- Nam Q. Le
Organizations
- United States Naval Research Laboratory