Abstract:
Density functional theory (DFT) has had a rapidly growing impact not only on fundamental but also industrial research. The local density approximation (LDA) and
the generalized gradient approximation (GGA) were used to compute the exchange
correlation energy. The total minimum energy of GaAs is performed as a function
of cutoff energy and Monk horst-pack grid size. The results show that, the total
minimum energy of GaAs decreases with increasing cutoff energy due to variational
principle. However, there is no systematic trend that can be predicted from just increasing the k point sampling. The total minimum force on GaAs is computed by
displacing As atom in the z direction as a function of cutoff energy and k point grid
size by 0.05 Bohr. Moreover, the total minimum force is converged at the cutoff 60
Rydberg and Monk horst-pack mesh of 14×14×14 k points. In addition to this, the
equilibrium lattice constant is calculated with different lattice constant.
