Generalized Pauli constraints in small atoms

Research output: Contribution to journalJournal articleResearchpeer-review

  • Christian Schilling
  • Murat Altunbulak
  • Stefan Knecht
  • Alexandre Lopes
  • James D. Whitfield
  • Christandl, Matthias
  • David Gross
  • Markus Reiher

The natural occupation numbers of fermionic systems are subject to nontrivial constraints, which include and extend the original Pauli principle. A recent mathematical breakthrough has clarified their mathematical structure and has opened up the possibility of a systematic analysis. Early investigations have found evidence that these constraints are exactly saturated in several physically relevant systems, e.g., in a certain electronic state of the beryllium atom. It has been suggested that, in such cases, the constraints, rather than the details of the Hamiltonian, dictate the system's qualitative behavior. Here, we revisit this question with state-of-the-art numerical methods for small atoms. We find that the constraints are, in fact, not exactly saturated, but that they lie much closer to the surface defined by the constraints than the geometry of the problem would suggest. While the results seem incompatible with the statement that the generalized Pauli constraints drive the behavior of these systems, they suggest that the qualitatively correct wave-function expansions can in some systems already be obtained on the basis of a limited number of Slater determinants, which is in line with numerical evidence from quantum chemistry.

Original languageEnglish
Article number052503
JournalPhysical Review A
Issue number5
Number of pages12
Publication statusPublished - 9 May 2018


ID: 197475169