Frozen density embedding with non-integer subsystems' particle numbers.

@article{Fabiano2014FrozenDE,
  title={Frozen density embedding with non-integer subsystems' particle numbers.},
  author={Eduardo Fabiano and Savio Laricchia and Fabio Della Sala},
  journal={The Journal of chemical physics},
  year={2014},
  volume={140 11},
  pages={
          114101
        }
}
We extend the frozen density embedding theory to non-integer subsystems' particles numbers. Different features of this formulation are discussed, with special concern for approximate embedding calculations. In particular, we highlight the relation between the non-integer particle-number partition scheme and the resulting embedding errors. Finally, we provide a discussion of the implications of the present theory for the derivative discontinuity issue and the calculation of chemical reactivity… 
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