• DOI:10.1103/PhysRevA.99.042109
• Corpus ID: 104292092

Orthogonalization of fermion k -body operators and representability

@article{Bach2018OrthogonalizationOF,
  title={Orthogonalization of fermion 
k
-body operators and representability},
  author={Volker Bach and Robert Rauch},
  journal={Physical Review A},
  year={2018}
}

• V. Bach, R. Rauch
• Published 13 July 2018
• Mathematics
• Physical Review A

The reduced k-particle density matrix of a density matrix on finite-dimensional, fermion Fock space can be defined as the image under the orthogonal projection in the Hilbert-Schmidt geometry onto the space of k-body observables. A proper understanding of this projection is therefore intimately related to the representability problem, a long-standing open problem in computational quantum chemistry. Given an orthonormal basis in the finite-dimensional one-particle Hilbert space, we explicitly construct an orthonormal basis of the space of Fock space operators which restricts to an orthonormal basis of the space of k-body operators for all k.