Well localized crystalline orbitals obtained from Bloch functions: The case of KNbO3 - art. no. 125102

The crystalline orbitals of KNbO3 are localized according to an iterative m ixed Wannier-Boys scheme. The transformed orbitals turn out to be extremely localized; their features and degree of localization are described in term s of various indices. The spontaneous polarization and the effective Born c harges of the various atoms are evaluated starting from the localized Wanni er function (LWF) centroids and from delocalized Bloch functions through th e Berry phase (BP) scheme. It turns out that the results provided by both a pproaches agree very well (for example, the spontaneous polarization is 0.3 361 and 0.3347 C/m(2) from the LWF and BP methods, respectively).