Structural, electronic and optical properties of the anhydrous orthorhombic 2C14H12Br2S3Bis (2-Bromobenzyl) trisulfide crystals

The C14H12Br2S3molecule has twofold imposed crystallographic symmetry in the solid state. 2C14H12Br2S3Bis (2-Bromobenzyl) trisulfide in the orthorhombic structure with space group P21212 is described and compared with other similar compounds. The structural, electronic, and optical properties of the anhydrous orthorhombic 2C14H12Br2S3Bis (2-Bromobenzyl) trisulfide crystals were treated within LDA/CA-PZ, GGA/PBE and GGA/PW91 approaches. The lattice parameters calculated with LDA/CA-PZ (a= 12.651 Å, b= 12.881 Å and c= 4.992 Å) are in better agreement with experimental values, where the error is 0.90 %, 1.14 %, and 4.79 % for a cutoff energy 240 eV. This calculation shows the usual trends, where the GGA/PBE and GGA/PW91 functional overestimate the lattice constant, unlike the LDA/CA-PZ. The C14H12Br2S3molecule has a large indirect band gap Z→Γ of 3.4498 eV and 3.5319 eV computed within LDA/CA-PZ and GGA/PBE approaches. The hybridization in the upper valence band between S: p, B: p and C: p, translates their covalent bonding. The Mulliken population charges show the zwitterionic state of the C14H12Br2S3molecule.