Approximating a wavefunction as an unconstrained sum of Slater determinants
- Department of Applied Mathematics, University of Colorado at Boulder, 256 UCB, Boulder, Colorado 80309-0526 (United States)
- Department of Mathematics, Ohio University, 321 Morton Hall, Athens, Ohio 45701 (United States)
The wavefunction for the multiparticle Schroedinger equation is a function of many variables and satisfies an antisymmetry condition, so it is natural to approximate it as a sum of Slater determinants. Many current methods do so, but they impose additional structural constraints on the determinants, such as orthogonality between orbitals or an excitation pattern. We present a method without any such constraints, by which we hope to obtain much more efficient expansions and insight into the inherent structure of the wavefunction. We use an integral formulation of the problem, a Green's function iteration, and a fitting procedure based on the computational paradigm of separated representations. The core procedure is the construction and solution of a matrix-integral system derived from antisymmetric inner products involving the potential operators. We show how to construct and solve this system with computational complexity competitive with current methods.
- OSTI ID:
- 21100228
- Journal Information:
- Journal of Mathematical Physics, Vol. 49, Issue 3; Other Information: DOI: 10.1063/1.2873123; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-2488
- Country of Publication:
- United States
- Language:
- English
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