Translationally invariant matrix elements of general one-body operators

Navratil, Petr

doi:10.48550/arxiv.2109.04017

Cited by 1 publication

(1 citation statement)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These densities are commonly used for the computation of one-body observables, such as matrix elements of electromagnetic operators for moments and transitions [44], and as inputs to reaction calculations [72]. More precisely, while the electromagnetic operators, taken properly in the center-of-mass frame, involve two-body or higher contributions, they may effectively be replaced by one-body operators when the center-of-mass motion has the harmonic-oscillator 0s form noted above [18,73]. The scalar densities (5), in particular, are also the necessary ingredient for deducing natural orbitals appropriate to the NCCI framework (Sec.…”

Section: B Natural Orbitals In the Ncci Frameworkmentioning

confidence: 99%

Natural orbitals for the ab initio no-core configuration interaction approach

Fasano,

Constantinou,

Caprio

et al. 2021

Preprint

View full text Add to dashboard Cite

Ab initio no-core configuration interaction (NCCI) calculations for the nuclear many-body problem have traditionally relied upon an antisymmetrized product (Slater determinant) basis built from harmonic oscillator orbitals. The accuracy of such calculations is limited by the finite dimensions which are computationally feasible for the truncated many-body space. We therefore seek to improve the accuracy obtained for a given basis size by optimizing the choice of single-particle orbitals. Natural orbitals, which diagonalize the one-body density matrix, provide a basis which maximizes the occupation of low-lying orbitals, thus accelerating convergence in a configuration-interaction basis, while also possibly providing physical insight into the single-particle structure of the many-body wave function. We describe the implementation of natural orbitals in the NCCI framework, and examine the nature of the natural orbitals thus obtained, the properties of the resulting many-body wave functions, and the convergence of observables. After taking 3 He as an illustrative testbed, we explore aspects of NCCI calculations with natural orbitals for the ground state of the p-shell neutron halo nucleus 6 He.

show abstract