Recent development of Monte Carlo shell model and its application to no-core calculations

24th IUPAP Conference on Computational Physics

物理学;计算机科学

Abe, T.^1 ; Maris, P.^2 ; Otsuka, T.^1,3,4 ; Shimizu, N.^3 ; Tsunoda, Y.^1 ; Utsuno, Y.^5 ; Vary, J.P.^2 ; Yoshida, T.^3

Department of Physics, University of Tokyo, Hongo, Tokyo 113-0033, Japan^1

Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, United States^2

Center for Nuclear Study, University of Tokyo, Hongo, Tokyo 113-0033, Japan^3

National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824, United States^4

Advanced Science Research Center, Japan Atomic Energy Agency, Tokai-Ibaraki 319-1195, Japan^5

关键词: Ab initio calculations;    Approximate methods;    Benchmark calculations;    Current limitation;    Full configuration interaction;    Hamiltonian matrix;    Lanczos iterations;    Many body wave functions;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/454/1/012066/pdf
DOI  :  10.1088/1742-6596/454/1/012066

学科分类：计算机科学（综合）

来源: IOP

【 摘 要 】

One of the major challenges in nuclear theory is to reproduce and to predict nuclear structure from ab initio calculations with realistic nuclear forces. As the current limitation of direct diagonalization of Hamiltonian matrices by Lanczos iteration method is around the order of matrix dimensionality 1010in shell-model calculations, it is difficult to access heavier nuclei beyond the p shell with sufficiently large basis spaces. It is possible to overcome this difficulty by utilizing efficient approximate methods to reproduce full ab initio solutions with good precision and quantified uncertainties. Following the major success of the Monte Carlo shell model (MCSM) with an assumed inert core in the sd- and pf-shell regions and also by recent developments in the MCSM algorithm, the no-core MCSM is expected to be one of the most powerful tools to meet these conditions. We have performed benchmark calculations in the p-shell region. Results of energies are compared with those in the full configuration interaction and no-core full configuration methods. These are found to be consistent with each other within quoted uncertainties when they could be quantified. We also compare and discuss the radial density of the helium-4 ground state extracted from the MCSM and FCI many-body wave functions.