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

Abstract

A new algorithm for calculating the spin- and parity-dependent shell model nuclear level densities using the moments method in the proton-neutron formalism is presented. A new, parallelized code based on this algorithm was developed and tested using up to 4000 cores for a set of nuclei from the sd-, pf-, and pf + g9/2 - model spaces. By comparing the nuclear level densities at low excitation energy for a given nucleus calculated in two model spaces, such as pf and pf + g9/2, one could estimate the ground state energy in the larger model space, which is not accessible to direct shell model calculations due to the unmanageable dimension. Examples for the ground state energies of for 64Ge and 68Se in the pf + g9/2 model space are presented.

10 pages, 7 figures, small corrections were made

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
• Improved basis selection for the Projected Configuration Interaction method applied to heavy nuclei
• Behavior of shell-model configuration moments
• Simple models for shell-model configuration densities

Cited by in corpus (20)

• Advanced density matrix renormalization group method for nuclear structure calculations
• Computational Nuclear Quantum Many-Body Problem: The UNEDF Project
• Novel Extrapolation Method in the Monte Carlo Shell Model
• Nuclear Level Density: Shell Model vs Mean Field
• A High-Performance Fortran Code to Calculate Spin- and Parity-Dependent Nuclear Level Densities
• Stochastic Estimation of Nuclear Level Density in the Nuclear Shell Model: An Application to Parity-Dependent Level Density in ${}^{58}$Ni
• Variational procedure for nuclear shell-model calculations and energy-variance extrapolation
• Benchmarking mean-field approximations to level densities
• Fast, Efficient Calculations of the Two-Body Matrix Elements of the Transition Operators for Neutrinoless Double Beta Decay
• Level-density parameters in superheavy nuclei
• High-Performance Algorithm for Calculating Non-Spurious Spin- and Parity-Dependent Nuclear Level Densities
• 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
• Microscopic model for the collective enhancement of nuclear level densities
• Microscopic description of neutron emission rates in compound nuclei
• Astrophysical reaction rates with realistic nuclear level densities
• UNEDF: Advanced Scientific Computing Collaboration Transforms the Low-Energy Nuclear Many-Body Problem
• Moments Method for Shell-Model Level Density
• Statistical Nuclear Spectroscopy with $q$-normal and bivariate $q$-normal distributions and $q$-Hermite polynomials
• Constant temperature description of the nuclear level densities