DFT-D studies on structural variation and absorption properties of crystalline benzotrifuroxan under high pressure

Abstract

The structural, electronic, and absorption properties of crystalline benzotrifuroxan (BTF) under hydrostatic compression of 0–150 GPa have been studied by using density functional theory with dispersion correction. The crystal structure of BTF was relaxed using three types of van der Waals corrections such as the PBE-G06, PBE-TS, and PW91-OBS functionals at ambient conditions. The results indicate that PBE-G06 is the best functional for studying BTF. The a and c directions may be more sensitive to van der Waals interactions than the b direction. The structure is the stiffest in the b direction in the whole pressure range. At 107 GPa, BTF decomposes by the breaking of the N2−O2 and O1−N6 bonds. An analysis of the band gap and density of states indicates that BTF becomes more and more sensitive under compression. The absorption spectra show that BTF has relatively high optical activity with increasing pressure; moreover, the absorption region is broadened in the energy range of below 1.5 and above 16.5 eV, respectively. This work may provide useful information in understanding how BTF behaves under high pressure.