Thermal expansion of energetic material TEX obtained from x-ray diffraction and first principles calculations

摘要: Abstract X-ray powder diffraction studies on the secondary explosive TEX (C6H6N4O8) in temperature range 25–150 °C are reported. has a triclinic structure (a = 6.850 A, b = 7.665 A, c = 8.826 A, α = 82.38°, β = 75.0°, and γ = 79.30° at 25 °C), space group P 1 ¯ . The crystal remains this range. From dependence of lattice parameters we find that thermal expansion is different along directions. volume coefficient 17.4 × 10−5 K-1 comparable to related material, CL-20. Thermal c-direction αc 2.2 times αa 3 αb. Phonon frequencies pressures obtained from density functional theory (DFT) calculations using CASTEP codes. calculated Gruneisen formalism 6.1 × 10−5 K-1. This first report experimental determination TEX, computation by DFT.