Please cite the following references:
 Luiz G. Ferreira, Marcelo Marques, and Lara K. Teles, "Approximation to density functional theory for the calculation of band gaps of semiconductors", Physical Review B 78, 125116 (2008).
 Jun-Hui Yuan, Qi Chen, Leonardo R. C. Fonseca, Ming Xu, Kan-Hao Xue and Xiang-Shui Miao, "GGA-1/2 self-energy correction for accurate band structure calculations: the case of resistive switching oxides", Journal of Physics Communications 2, 105005 (2018).
For information and references for the VASP code, please visit: http://www.vasp.at
The self-energy potentials were generated by atom/ion calculations using ATOM, a program for DFT calculations in atoms and pseudopotential generation, maintained by Alberto Garcia.