An efficient method to evaluate energy variances for extrapolation methods

Abstract

The energy variance extrapolation method consists in relating the approximate energies in many-body calculations to the corresponding energy variances and inferring eigenvalues by extrapolating to zero variance. The method needs a fast evaluation of the energy variances. For many-body methods that expand the nuclear wave functions in terms of deformed Slater determinants, the best available method for the evaluation of energy variances scales with the sixth power of the number of single-particle states. We propose a new method which depends on the number of single-particle orbits and the number of particles rather than the number of single-particle states. We discuss as an example the case of ${}^{4}He$ using the chiral N3LO interaction in a basis consisting up to 184 single-particle states.

16 pages, 2 figures

References in corpus (3)

• Ab initio coupled-cluster approach to nuclear structure with modern nucleon-nucleon interactions
• Novel Extrapolation Method in the Monte Carlo Shell Model
• Ab-initio calculation of the ${}^{6}Li$ binding energy with the Hybrid Multideterminant scheme

Cited by in corpus (5)

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• A study of open shell nuclei using chiral two-body interactions
• Effect of residual many-body forces due to the evolution in the in-medium similarity renormalization group method
• Many-body calculations with Deuteron based single-particle bases and their associated natural orbits