Optimization of PAO by yourself

Starting from the primitive basis functions, you can optimize the radial shape variationally so that the accuracy can be increased. See the details in the Section 'Orbital optimization'.

Figure 3: The isosurface map of the highest occupied state at the $\Gamma $ point for NaCl with a Cl-site vacancy, which shows a F-center in NaCl with a Cl vacancy. The isosurface map was drawn using XCrySDen with the isovalue of 0.042 [105]. The calculation was done with the system charge of -1 using a keyword 'scf.system.charge'. The watery and silver colors correspond to sodium and chlorine atoms,respectively, and the yellow small ball shows the position of empty atom.