Stability of Stone–Wales defect in two-dimensional honeycomb crystals

We have studied the valence effects on the stability of Stone-Wales (SW) defect in some typical two-dimensional honeycomb crystals containing group-IV, V, and VI elements employing density functional theory. The energetics involved in an in-plane formation process of SW defects in pristine and substitutionally doped materials is simulated. The SW defects are stable and have a rotation angle about 90 degree in the group-IV materials. They may become less stable with a smaller rotation angle in the group-V materials and seem difficult to exist in the group-VI materials. Group-VI doping may help eliminate SW defects while group-IV and V doping might introduce SW defects in some group-VI compounds.