title: Density Functional Partition Theory with Fractional Occupations.
abstract: Partition theory (PT) is a formally exact methodology for calculating the density of any molecule or solid via separate calculations on individual fragments. Just as Kohn-Sham density functional theory (DFT) introduces noninteracting fermions in an effective potential that is defined to yield the exact density of the interacting problem, in PT a global effective potential is found that ensures that the sum of the fragment densities is that of the full system. By combining the two, density functional partition theory (DFPT) produces a DFT scheme that yields the (in principle) exact molecular density and energy via Kohn-Sham calculations on fragments. We give the full formalism and illustrate DFPT in the general case of noninteger fragment occupations.
authors.affiliation: Department of Physics and Astronomy, University of California, Irvine, California 92697, Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, New Jersey 08854, Department of Chemistry, Princeton University, Washington Road, Princeton, New Jersey 08544, Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, and Department of Chemistry, University of California, Irvine, California 92697.
authors.forename: Peter
authors.initials: P
authors.lastname: Elliott
authors.affiliation: Department of Physics and Astronomy, University of California, Irvine, California 92697, Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, New Jersey 08854, Department of Chemistry, Princeton University, Washington Road, Princeton, New Jersey 08544, Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, and Department of Chemistry, University of California, Irvine, California 92697.
authors.forename: Morrel H
authors.initials: MH
authors.lastname: Cohen
authors.affiliation: Department of Physics and Astronomy, University of California, Irvine, California 92697, Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, New Jersey 08854, Department of Chemistry, Princeton University, Washington Road, Princeton, New Jersey 08544, Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, and Department of Chemistry, University of California, Irvine, California 92697.
authors.forename: Adam
authors.initials: A
authors.lastname: Wasserman
authors.affiliation: Department of Physics and Astronomy, University of California, Irvine, California 92697, Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, New Jersey 08854, Department of Chemistry, Princeton University, Washington Road, Princeton, New Jersey 08544, Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, and Department of Chemistry, University of California, Irvine, California 92697.
authors.forename: Kieron
authors.initials: K
authors.lastname: Burke