We have studied BGO:Nd electronic structure in the energy region around the band gap, treating f electrons in two different ways, first as localized (using the open-core approximation), and second as delocalized. The aim is to investigate the changes in electronic properties of the BGO:Nd by analyzing the character and the position of the electronic states introduced by Nd. DFT was used within LAPW basis functions. The effects of exchange and correlation were simulated according to the GGA. Optical properties of BGO:Nd were also analyzed. The absorption spectrum is found to be similar for both treatments. (C) 2013 Published by Elsevier B. V.