Total energy calculations

We apply the density functional theory (DFT) approach by using the Vienna Ab Initio Simulation Package (VASP) package¹ to calculate the total energy of carbon allotropes. The Generalized Gradient Approximation² (GGA) for exchange-correlational functional is used everywhere. The energy cutoff set to 600 eV. Fully automatic Γ-centered k-points mesh with a reciprocal-space resolution of 2π × 0.025 Å⁻¹ is applied. We used tetrahedron method with Blöchl corrections to perform the k-point integration. The convergence thresholds are set at 10⁻⁶ eV for energy and 10⁻⁵ eV Å⁻¹ for ionic forces.

References

¹ G. Kresse, J. Furthmüller Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set . Phys. Rev. 1996, B 54, 11169–11186.

² J. P. Perdew, K. Burke, M. Ernzerhof Generalized gradient approximation made simple . Phys. Rev. Lett. 1996, 77, 3865–3868.