“…This semi-empirical method is best viewed as an approximation to DFT, and is parameterized based on LDA-DFT calculations. It has been tested and shown to reproduce, quite accurately, the mechanical properties of brittle materials such as diamond, CNTs, and graphene, as predicted by DFT, while being on the order of 100 times faster than DFT based on first-principles (Elstner et al, 1998(Elstner et al, , 2000Frauenheim et al, 2002).…”