These pseudopotentials are a reproduction of the SG15 Optimized Norm-Conserving Vanderbilt (ONCV) pseudopotentials using the ONCVPSP-4.0.1 (beta release) code by D. R. Hamann.
The main reason for this repository is to have a set of SG15 pseudopotentials in the psp8 format created with the latest version of ONCVPSP code (and the corresponding upf format, note that due to the difference in the version of ONCVPSP code used here, the pseudopotentials in the UPF format may not be exactly the same as the original ones), which is not provided in the SG15 pseudopotentials set. Users should cite the original papers listed on the SG15 website.
[1] M. Schlipf and F. Gygi, Computer Physics Communications 196, 36 (2015). http://dx.doi.org/10.1016/j.cpc.2015.05.011.
[2] D. R. Hamann, Phys. Rev. B 88, 085117 (2013). http://link.aps.org/doi/10.1103/PhysRevB.88.085117