ELECTRONIC-STRUCTURE OF PRBA2CU3O7 FROM LAPW BAND-STRUCTURE CALCULATIONS

We have performed band structure calculations for PrBa2Cu3O7 using the full-potential LAPW method, which is based on density functional theo ry. The Pr 4f electrons are treated as valence states and form narrow bands at the Fermi level. Furthermore we have simulated a Pr valency o f 3+ (4+) by treating the Pr 4f states as localized states with a fixe d occupation of 2 (1). We have determined partial charges, densities o f states, difference densities, electric field gradients, and their as ymmetry parameters for this system and discuss the differences between the 'itinerant case' and the two model calculations representing the localized f states. The corresponding total energies yield the results that the itinerant f states are the most stable, followed by Pr with a 3+ valency, and the 4+ being the least stable. The overall electroni c structure obtained by the itinerant calculation is rather close to t he trivalent Pr case.