The Ge-doped (6,0) zigzag single-walled boron phosphide nanotubes: A computational study

Electronic structure properties including bond lengths, bond angles, tip diameters, dipole moments (mu), energies, band gaps, NMR, and NQR parameters were calculated using density functional theory for Ge-doped boron phosphide nanotubes (BPNTs). Geometry optimizations were carried out at the B3LYP/6-31G* level of theory the Gaussian 03 program suites. The isotropic (CSI) and anisotropic (CSA) chemical shielding parameters for the sites of various B-11 and P-31 atoms, and quadrupole coupling constant (C-Q) and asymmetry parameter (eta(Q)) at the sites of various B-11 nuclei were calculated for Ge-doped (6,0) zigzag BPNT models. The calculations indicated that average B-P bond lengths of the Ge-B model are larger than average B-P bond lengths of pristine and the Ge-p models. For the Ge-B and Ge-p models, the diameters values changes were almost negligible. The dipole moments of the two Ge-doped BPNT structures show slightly changes due to the Ge-doping with respect to the pristine model. In comparison with the pristine model, band gaps of the two Ge-doped models are reduced and increase their electrical conductance. The changes in the NMR and NQR parameters due to the Ge-doping are more significant for the Ge-B model than for the Ge-p model with respect to the pristine model. (C) 2011 Elsevier B.V. All rights reserved.