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Energy as a functional of the density matrix
Author(s) -
Berrondo M.,
Goscinski O.
Publication year - 2009
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.560090812
Subject(s) - density matrix , hamiltonian (control theory) , matrix (chemical analysis) , density functional theory , energy density , hamiltonian matrix , energy (signal processing) , limit (mathematics) , ground state , physics , energy functional , function (biology) , quantum mechanics , chemistry , mathematical analysis , mathematics , symmetric matrix , mathematical optimization , eigenvalues and eigenvectors , theoretical physics , chromatography , quantum , evolutionary biology , biology
A variational principle is presented for the ground state energy in terms of the one‐particle density matrix. The functional expression of the energy in terms of the density matrix is obtained as the limit of zero temperature of the free energy. This is achieved by adding a nonlocal external potential to the N ‐body Hamiltonian and obtaining a renormalized equation for the density matrix instead of the Green's function. By eliminating the external source it was possible to express the energy as a functional of the density matrix.