2020/09/30 by Jens Hoppe, J. Hoppe, A. Tichai +3
Chemistry · Mathematics · Physics and Astronomy · #Advanced Chemical Physics Studies #Advanced NMR Techniques and Applications #Atomic orbital #Basis (linear algebra) #Basis set #Benchmark (surveying) #Computer science #Density functional theory #Geometry #Mathematics #Nuclear physics research studies #Physics #Quantum mechanics #Statistical physics #nucl-th
paper · pdf · doi:10.1103/physrevc.103.014321
published as Phys. Rev. C 103, 014321 (2021) · 15 pages, 9 figures, published version
openalex publication_date 2021/01/28 · arxiv created 2021/02/01 · arxiv updated 2021/02/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The nuclear many-body problem for medium-mass systems is commonly addressed using wave-function expansion methods that build upon a second-quantized representation of many-body operators with respect to a chosen computational basis. While various options for the computational basis are available, perturbatively constructed natural orbitals recently have been shown to lead to significant improvement in many-body applications yielding faster model-space convergence and lower sensitivity to basis set parameters in large-scale no-core shell model diagonalizations. This work provides a detailed comparison of single-particle basis sets and a systematic benchmark of natural orbitals in nonperturbative many-body calculations using the in-medium similarity renormalization group approach. As a key outcome we find that the construction of natural orbitals in a large single-particle basis enables for performing the many-body calculation in a reduced space of much lower dimension, thus offering significant computational savings in practice that help extend the reach of ab initio methods towards heavier masses and higher accuracy.