Just a comment about the "box grid": note that this is used for both the "augmentation charge" in Ultrasoft pseudopotentials, and for the "core charge" used for the nonlinear core correction. All boxes are of the same size, so the "larger" charge determines the minimum size of the box.
References: Phys. Rev. B 47, 10142 (1993); JCP 120, 5903 (2004) Paolo -- Paolo Giannozzi e-mail: giannozz at nest.sns.it Scuola Normale Superiore Phone: +39/050-509876, Fax:-563513 Piazza dei Cavalieri 7 I-56126 Pisa, Italy
