The influence of the double-ring nanotubules diameter of B n (n = 14, 20, 24 and 32) on the electronic and structural properties due to lithium atom doping: quantum chemistry approach

Quantum chemistry approach through density functional theory has been selected to provide clear vision about electronic and structural features of two Li atoms doping to the double-ring nanotubules of the Bn (n = 14, 20, 24 and 32). For each the 2Li@Bn (n = 14, 20, 24 and 32) molecules, we have reported two more stable geometries due to doping of two Li atoms to the Bn (n = 14, 20, 24 and 32) backbones. The stability evaluation of the reported molecules through adsorption, deformation, and vertical ionization energies along with energy gap of HOMO–LUMO orbitals has been studied on the singlet potential energy surface. Additionally, three analyses of atoms in molecule, electron transfer, and first hyperpolarizability have been performed on the reported molecules of the 2Li@Bn (n = 14, 20, 24 and 32) systems. The calculated results reflect that the Li atoms move to space inside of the Bn (n = 14, 20, 24 and 32) backbones along with increasing double-ring diameter. Also, these is the reverse relation between thermodynamic and chemical stabilities and double-ring diameter in the 2Li@Bn (n = 14, 20, 24 and 32) molecules. In contrast, the direct relation has been found between the value of the first hyperpolarizability and double-ring diameter from the B14 to the B20 backbone. Additionally, the change of double-ring size of the Bn (n = 14, 20, 24 and 32) backbones has not significant influence on vertical ionization energy. Finally, the B atoms of the Bn (n = 14, 20, 24 and 32) backbones have high chemical flexibility in electron transfer process from two Li atoms to the Bn (n = 14, 20, 24 and 32) backbones.