FELIX2.0: New version of the finite element solver for the time dependent generator coordinate method with the Gaussian overlap approximation
Abstract
The timedependent generator coordinate method (TDGCM) is a powerful method to study the largeamplitude collective motion of quantum manybody systems such as atomic nuclei. Under the GaussianOverlap Approximation (GOA), the TDGCM leads to a local, timedependent Schrödinger equation in amultidimensional collective space. In this paper, we present the version 2.0 of the code FELIX that solvesthe collective Schrödinger equation in a finite element basis. This new version features: (i) the ability tosolve a generalized TDGCM+GOA equation with a metric term in the collective Hamiltonian, (ii) supportfor new kinds of finite elements and different types of quadrature to compute the discretized Hamiltonianand overlap matrices, (iii) the possibility to leverage the spectral element scheme, (iv) an explicit Krylovapproximation of the time propagator for time integration instead of the implicit Crank–Nicolson methodimplemented in the first version, (v) an entirely redesigned workflow. We benchmark this release on ananalytic problem as well as on realistic twodimensional calculations of the lowenergy fission of240Puand256Fm. Low to moderate numerical precision calculations are most efficiently performed with simplexelements with a degree 2 polynomial basis. Higher precision calculations should instead use the spectralelement method with a degree 4 polynomial basis. We emphasize that in a realistic calculation of fissionmass distributionsmore »
 Authors:

 Université ParisSud, Orsay Cedex, (France). Institut de Physique Nucléaire
 CEA, DAM, DIF, Arpajon (France).
 Lawrence Livermore National Laboratory. (LLNL), Livermore, CA (United States). Nuclear and Chemical Science Division
 Publication Date:
 Research Org.:
 Oak Ridge National Laboratory, Oak Ridge Leadership Computing Facility (OLCF); Lawrence Berkeley National Laboratory, Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC).
 Sponsoring Org.:
 USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR) (SC21)
 OSTI Identifier:
 1463274
 DOE Contract Number:
 AC5207NA27344; AC0500OR22725; AC0205CH11231
 Resource Type:
 Journal Article
 Journal Name:
 Computer Physics Communications
 Additional Journal Information:
 Journal Volume: 225; Journal Issue: C; Journal ID: ISSN 00104655
 Country of Publication:
 United States
 Language:
 English
Citation Formats
Regnier, D., Dubray, N., Verri�re, M., and Schunck, N. FELIX2.0: New version of the finite element solver for the time dependent generator coordinate method with the Gaussian overlap approximation. United States: N. p., 2018.
Web. doi:10.1016/j.cpc.2017.12.007.
Regnier, D., Dubray, N., Verri�re, M., & Schunck, N. FELIX2.0: New version of the finite element solver for the time dependent generator coordinate method with the Gaussian overlap approximation. United States. doi:10.1016/j.cpc.2017.12.007.
Regnier, D., Dubray, N., Verri�re, M., and Schunck, N. Sun .
"FELIX2.0: New version of the finite element solver for the time dependent generator coordinate method with the Gaussian overlap approximation". United States. doi:10.1016/j.cpc.2017.12.007.
@article{osti_1463274,
title = {FELIX2.0: New version of the finite element solver for the time dependent generator coordinate method with the Gaussian overlap approximation},
author = {Regnier, D. and Dubray, N. and Verri�re, M. and Schunck, N.},
abstractNote = {The timedependent generator coordinate method (TDGCM) is a powerful method to study the largeamplitude collective motion of quantum manybody systems such as atomic nuclei. Under the GaussianOverlap Approximation (GOA), the TDGCM leads to a local, timedependent Schrödinger equation in amultidimensional collective space. In this paper, we present the version 2.0 of the code FELIX that solvesthe collective Schrödinger equation in a finite element basis. This new version features: (i) the ability tosolve a generalized TDGCM+GOA equation with a metric term in the collective Hamiltonian, (ii) supportfor new kinds of finite elements and different types of quadrature to compute the discretized Hamiltonianand overlap matrices, (iii) the possibility to leverage the spectral element scheme, (iv) an explicit Krylovapproximation of the time propagator for time integration instead of the implicit Crank–Nicolson methodimplemented in the first version, (v) an entirely redesigned workflow. We benchmark this release on ananalytic problem as well as on realistic twodimensional calculations of the lowenergy fission of240Puand256Fm. Low to moderate numerical precision calculations are most efficiently performed with simplexelements with a degree 2 polynomial basis. Higher precision calculations should instead use the spectralelement method with a degree 4 polynomial basis. We emphasize that in a realistic calculation of fissionmass distributions of240Pu, FELIX2.0 is about 20 times faster than its previous release (within a numericalprecision of a few percents).},
doi = {10.1016/j.cpc.2017.12.007},
journal = {Computer Physics Communications},
issn = {00104655},
number = C,
volume = 225,
place = {United States},
year = {2018},
month = {4}
}