Exactness of two-body cluster expansions in many-body quantum theory.

The Horn-Weinstein formula and the variational principle, combined with numerical results for a few many-electron systems, are used to provide support for a conjecture that the exact ground-state wave function for a Hamiltonian system containing up to two-body terms may be represented by an exponential cluster expansion employing a finite two-body operator.

[1]  Hiroshi Nakatsuji,et al.  Structure of the exact wave function. II. Iterative configuration interaction method , 2001 .

[2]  H. Nakatsuji.  Structure of the exact wave function. IV. Excited states from exponential ansatz and comparative calculations by the iterative configuration interaction and extended coupled cluster theories , 2002 .

[3]  Weinstein,et al.  The t expansion and SU(2) lattice gauge theory. , 1985, Physical review. D, Particles and fields.

[4]  Marko,et al.  t-expansion and connected-moment expansion: A generalization to excited states. , 1990, Physical review. D, Particles and fields.

[5]  Martin Head-Gordon,et al.  Two-body coupled cluster expansions , 2001 .

[6]  Hiroshi Nakatsuji,et al.  Structure of the exact wave function , 2000 .

[7]  D. Horn,et al.  T expansion: A nonperturbative analytic tool for Hamiltonian systems , 1984 .

[8]  F. Coester,et al.  Bound states of a many-particle system , 1958 .

[9]  Cioslowski.  Connected moments expansion: A new tool for quantum many-body theory. , 1987, Physical review letters.

[10]  H. Nakatsuji.  Structure of the exact wave function. III. Exponential ansatz , 2001 .

[11]  Nooijen.  Can the eigenstates of a many-body hamiltonian Be represented exactly using a general two-body cluster expansion? , 2000, Physical review letters.

[12]  Leszek Meissner,et al.  Davidson-type corrections for quasidegenerate states , 1985 .

[13]  J. Cizek.  On the Correlation Problem in Atomic and Molecular Systems. Calculation of Wavefunction Components in Ursell-Type Expansion Using Quantum-Field Theoretical Methods , 1966 .

[14]  D. Horn,et al.  The axial glueball in lattice QCD , 1986 .

[15]  Josef Paldus,et al.  Applicability of coupled‐pair theories to quasidegenerate electronic states: A model study , 1980 .