upward

Optimized atomic orbitals

M Chen, W Fang, G Sun, G Guo, L He, Method to construct transferable minimal basis sets for ab initio calculations, PRB 80, 165121 (2009)

M Gusso, Study on the maximum accuracy of the pseudopotential density functional method with localized atomic orbitals versus plane-wave basis sets, JCP 128, 044102 (2008)