Correlation Induced Optimization of Wave Functions: the Hubbard Chain
J. Spałek, R. Podsiadły
Marian Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Kraków, Poland

and W. Wójcik
Institute of Physics, Tadeusz Kościuszko Technical University, Podchorążych 1, 30-084 Kraków, Poland

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We determine the explicit form of the single-particle Wannier functions {wi(r)} appearing in the parameters of quantum models. The method is illustrated on the example of the Hubbard chain, for which we derive the renormalized wave equation starting from a variational principle and by treating the system ground state energy as a functional of {wi(r)} and their derivatives. In this manner, the optimized basis is obtained only after the electronic correlations have been included in the rigorous Lieb-Wu solution. The results for the ground state energy and the size of the renormalized s-type orbitals, both as a function of interatomic distance, are calculated explicitly.
DOI: 10.12693/APhysPolA.97.381
PACS numbers: 71.10.Fd, 71.15.Fv, 31.25.Nj