Search for negative U in the Ba1-xKxBi1-yPbyO3 system using constrained density-functional theory.

@article{Vielsack1996SearchFN,
  title={Search for negative U in the Ba1-xKxBi1-yPbyO3 system using constrained density-functional theory.},
  author={Vielsack and J H Weber},
  journal={Physical review. B, Condensed matter},
  year={1996},
  volume={54 9},
  pages={6614-6623}
}