Electronic properties and Hirshfeld surface analysis of dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate under pressure

Abstract

We present ab initio calculations to investigate the pressure induced variations in the electronic structure of dihydroxyl-ammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50) using empirical dispersion correction method proposed by Grimme (DFT-D2). The calculated electronic band structure using Tran-Blaha modified Becke Johnson (TB-mBJ) potential show that TKX-50 is an indirect band gap insulator along C-B direction with a band gap of 4.018 eV, while the band gap obtained with standard generalized gradient approximation is 3.54 eV. The electronic band gap of TKX-50 is found to decrease monotonically as a function of pressure. We also performed the Hirshfeld surface calculations and the corresponding 2-D fingerprint analysis to understand the nature of intermolecular interactions and their quantitative contributions towards the crystal packing. The largest percentage of TKX-50 molecule is due to N.H/H.N and O.H/H.O contacts (∼70%), which represents hydrogen bonding networks as the primary intermolecular interactions and also responsible for the low sensitivity of TKX-50.