Basis set effect on defect induced spin polarization of a carbon nanotube in density functional theory calculations.

Highlights: [•] A polarization function independent ground state (triplet) in a single carbon defect case. [•] A polarization function dependent ground state (triplet vs quintet) in a double carbon defect case. [•] Polarization function caused s and p contribution changes and thus the strong basis set effect. [Copyright &y& Elsevier]