A High-Performance Fortran Code to Calculate Spin- and Parity-Dependent Nuclear Level Densities

Abstract

A high-performance Fortran code is developed to calculate the spin- and parity-dependent shell model nuclear level densities.The algorithm is based on the extension of methods of statistical spectroscopy and implies exact calculation of the first and second Hamiltonian moments for different configurations at fixed spin and parity. The proton-neutron formalism is used. We have applied the method for calculating the level densities for a set of nuclei in the sd-, pf-, and pf+g9/2 - model spaces. Examples of the calculations for 28Si (in the sd-model space) and 64Ge (in the pf+g9/2-model space) are presented. To illustrate the power of the method we estimate the ground state energy of 64Ge in the larger model space pf+g9/2, which is not accessible to direct shell model diagonalization due to the prohibitively large dimension, by comparing with the nuclear level densities at low excitation energy calculated in the smaller model space pf.

9 pages, 4 figures, 1 table, code description (readme.txt) is attached. arXiv admin note: substantial text overlap with arXiv:1004.5027

References in corpus (7)

• Spin projection in the shell model Monte Carlo method and the spin distribution of nuclear level densities
• Heavy deformed nuclei in the shell model Monte Carlo method
• Large-scale prediction of the parity distribution in the nuclear level density and application to astrophysical reaction rates
• Angular Momentum Projected Configuration Interaction with Realistic Hamiltonians
• High-Performance Algorithm for Calculating Non-Spurious Spin- and Parity-Dependent Nuclear Level Densities
• Simple models for shell-model configuration densities
• Combinatorial nuclear level-density model

Cited by in corpus (20)

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• From bound states to the continuum
• Computational Nuclear Quantum Many-Body Problem: The UNEDF Project
• Nuclear Level Density: Shell Model vs Mean Field
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• Nuclear shape transitions, level density, and underlying interactions
• Microscopic calculations of nuclear level densities with the Lanczos method
• Quantum phase transitions and collective enhancement of level density in odd-A and odd-odd nuclei
• Level density of the $sd$-nuclei $-$ statistical shell-model predictions
• Projected shell model description of nuclear level density: Collective, pair-breaking, and multiquasiparticle regimes in even-even nuclei
• Nuclear level density from relativistic density functional theory and combinatorial method
• Astrophysical reaction rates with realistic nuclear level densities
• Nuclear level densities: from empirical models to microscopic methods
• Constraining level densities through quantitative correlations with cross-section data
• Inference of Parameters for Back-shifted Fermi Gas Model using Feedback Neural Network
• Statistical Nuclear Spectroscopy with $q$-normal and bivariate $q$-normal distributions and $q$-Hermite polynomials
• Moments Method for Shell-Model Level Density
• New equilibrium ensembles for isolated quantum systems
• Combinatorial level densities by the real-time method
• Constant temperature description of the nuclear level densities