NMR and NQR parameters of Si-doped (6,0) zigzag single-walled boron phosphide nanotubes: a density functional study

Abstract

Electronic structure properties including bond lengths, bond angles, tip diameters, dipole moments, energies, band gaps, and nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) parameters were calculated using density functional theory (DFT) for Si-doped boron phosphide nanotubes (BPNTs). Geometry optimizations were carried out at the B3LYP/6-31G* level of theory using the Gaussian 03 program suite. The chemical shielding parameters for the sites of various 29Si, 11B, and 31P atoms, and quadrupole coupling constants and asymmetry parameters at the sites of various 11B nuclei, were calculated for the Si-doped (6,0) zigzag BPNT models. The dipole moments and average B–P bond lengths of the Si-doped BPNT structures show slight changes between the Si-doped and pristine models. For the SiB model the diameter values are increased, whereas in the SiP model the changes of the diameter values are negligible. In comparison with the pristine model, the band gaps of the SiB and SiP models are reduced, whereas their electrical conductance is increased. Comparison of the NMR and NQR parameters calculated for the SiB and SiP models showed that the electronic structure properties of the SiB (6,0) zigzag BPNT model are more strongly influenced than those of the SiP model.