ShellModel.jl

Julia code for nuclear shell-model calculations

Note:
This package has been merged into NuclearToolkit.jl, though the repository will be kept for reproducibility of the published work.

1. Download a Julia binary from Julialang.org
   or execute the following when using a Linux(-like) environment:

$wget https://julialang-s3.julialang.org/bin/linux/x64/1.6/julia-1.6.0-linux-x86_64.tar.gz

2. Set a path to Julia. Then you can run Julia REPL

$julia
               _
   _       _ _(_)_     |  Documentation: https://docs.julialang.org
  (_)     | (_) (_)    |
   _ _   _| |_  __ _   |  Type "?" for help, "]?" for Pkg help.
  | | | | | | |/ _` |  |
  | | |_| | | | (_| |  |  Version 1.6.0 (2021-03-24)
 _/ |\__'_|_|_|\__'_|  |  Official https://julialang.org/ release
|__/                   |

julia>

3. Download ShellModel.jl

$git clone https://github.com/SotaYoshida/ShellModel.jl

4. Install other Julia Packages

$cd ShellModel.jl
$julia src/package_install.jl

5. Run the sample script

$julia -t 12 sample_run.jl

One can specify the number of execution threads like this.
(The -t/--threads command line argument requires at least Julia >= 1.5.)

Note: The samplecode is to calc.
(a) 10 lowest states of 28Si in sd shell
(b) 10 lowest states of 28Si with J=0
(c) EC estimates of 10 lowest J=0 states of 28Si
(d) (b) with the preprocessing

Here

• Pros (Some are "Pros" of the Julia language though :D)
  • Easy to run
  • Portability (no need to specify "magical" compiler options specific to each environment)
  • Fast (e.g., 10 lowest eigenpairs of 28Si (in full sd shell) can be calculated in ~3 sec. on Mac Mini(2018) & Mac Book Air(2020,M1))
  • One can easily extend the code
• Cons
  • poorly parallerized (for # of threads >= 12)
  • greedy (compared to the "on-the-fly" generation of matrix element)
  • one is recommended to include "initial run" for a small system (e.g. Be8 in p shell) in execution scripts
    This is for JIT compilation of the functions to improve the execution time for a target system.
    You can also try PackageCompiler.jl

• To obtain lowest n eigenvalues, eigenvectors (in M-scheme)
  ※ One can specify the total J
  ※ The current version only supports model spaces with one major shell
  (i.e., the so-called "0 hbar omega" space such as sd shell)
  ※ interaction fmt: KSHELL fmt (.snt) only

• Eigenvector Continuation (To constuct approximate shell-model wave funcitons for a given effective interaction) as efficient emulator & preprocessing for the shell-model

• Calc. mu & Q moments and M1, E2 transitions (April 2021 -)

• Calc. entanglement entropy

• truncations
• compatibility to other interaction fmt
• compatibility to wavefunctions by other shell-model codes
• J-scheme
• other operators (Gamow-Teller, etc.)
• spectroscopic factors
• DMRG
• MPI parallerization for larger systems
• and more...

Any suggestions, feedbacks, and "Issues&Pull requests" are welcomed.

MIT License, Copyright (c) 2021 Sota Yoshida

Prog. Theor. Exp. Phys. 2022 053D02 (2022)