4 research outputs found
Benchmark calculation of no-core Monte Carlo shell model in light nuclei
The Monte Carlo shell model is firstly applied to the calculation of the
no-core shell model in light nuclei. The results are compared with those of the
full configuration interaction. The agreements between them are within a few %
at most.Comment: 4 pages, 1 figure, 1 table, Proceedings of the International
Symposium on New Faces of Atomic Nuclei, Okinawa, Japan, Nov. 15-17, 201
Benchmarks of the full configuration interaction, Monte Carlo shell model, and no-core full configuration methods
We report no-core solutions for properties of light nuclei with three
different approaches in order to assess the accuracy and convergence rates of
each method. Full configuration interaction (FCI), Monte Carlo shell model
(MCSM) and no core full configuration (NCFC) approaches are solved separately
for the ground state energy and other properties of seven light nuclei using
the realistic JISP16 nucleon-nucleon interaction. The results are consistent
among the different approaches. The methods differ significantly in how the
required computational resources scale with increasing particle number for a
given accuracy.Comment: 19 pages, 14 figures, 6 table
An efficient method to evaluate energy variances for extrapolation methods
The energy variance extrapolation method consists in relating the approximate
energies in many-body calculations to the corresponding energy variances and
inferring eigenvalues by extrapolating to zero variance. The method needs a
fast evaluation of the energy variances. For many-body methods that expand the
nuclear wave functions in terms of deformed Slater determinants, the best
available method for the evaluation of energy variances scales with the sixth
power of the number of single-particle states. We propose a new method which
depends on the number of single-particle orbits and the number of particles
rather than the number of single-particle states. We discuss as an example the
case of using the chiral N3LO interaction in a basis consisting up to
184 single-particle states.Comment: 16 pages, 2 figure
Monte Carlo Shell Model for ab initio nuclear structure
We report on our recent application of the Monte Carlo Shell Model to no-core calculations. At the initial stage of the application, we have performed benchmark calculations in the p-shell region. Results 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. The preliminary results in Nshell = 5 reveal the onset of systematic convergence pattern