Computational science

Relativistic quantum chemistry

Pure mathematics

Nuclear physics

Fortran

Parallel computing

Computer science

Physics

Mathematics

Programming language

Algebra over a field

Computer Physics Communications

The present null Grasp null 2018 is an updated null Fortran null 95 version of the recommended block versions of programs from null null Grasp null 2K Version 1_1 for large-scale calculations Jonsson et al. (2013). MPI programs are included so that all major tasks can be executed using parallel computers. Tools have been added that simplify the generation of configuration state function expansions for the multireference single- and double computational model. Names of programs have been changed to accurately reflect the task performed by the code. Modifications to the relativistic self-consistent field program have been made that, in some instances, greatly reduce the number of iterations needed for determining the requested null eigenvalues null null and the memory required. Changes have been made to the relativistic configuration interaction program to substantially cut down on the time for constructing the null Hamiltonian null matrix for configuration state function expansions based on large orbital sets. In the case of a finite nucleus the grid points have been changed so that the first non-zero point is Z-dependent as for the point nucleus. A number of tools have been developed to generate LaTeX tables of eigenvalue composition, energies, transition data and lifetimes. Tools for plotting and analyzing computed properties along an iso-electronic sequence have also been added. A number of minor errors have been corrected. A detailed manual is included that describes different aspects of the package as well as the steps needed in order to produce reliable results. null null null null null Program summary null Program Title: null Grasp 2018 null Program Files doi: null http://dx.doi.org/10.17632/x574wpp2vg.1 null null Licensing provisions: MIT license null Programming language: Fortran 95. null Nature of problem: null Prediction of atomic properties –  atomic energy levels null null , null isotope shifts null null , null oscillator strengths , radiative decay rates, null null hyperfine structure null parameters, specific mass shift parameters, null null null Zeeman effects null – using a multiconfiguration Dirac–Hartree–Fock approach. null null null Solution method: The computational method is the same as in the previous null Grasp 2K [1,2] version except that only the latest recommended versions of certain routines are included. null Restrictions: null All calculations are for bound state solutions. Instead of relying on null packing algorithms null for specifying arguments of arrays of integrals, orbitals are designated by a “short integer” requiring one byte of memory for a maximum of 127 orbitals. The tables of reduced coefficients of fractional parentage used in this version are limited to sub-shells with null null null null j null ≤ null 9 null ∕ null 2 null null null [3]; occupied sub-shells with null null null j null > null 9 null ∕ null 2 null null null are, therefore, restricted to a maximum of two electrons. Some other parameters, such as the maximum number of orbitals are determined in a null parameter_def_M.f90 null file that can be modified prior to compile time. null Unusual features: Parallel versions are available for several applications. null References null null • null null [[1]] P. Jonsson, X. He, C. Froese Fischer, and I. P. Grant, Comput. Phys. Commun. 176, 597 (2007). null null • null null [[2]] P. Jonsson, G. Gaigalas, J. Bieron, C. Froese Fischer, and I. P. Grant, Comput. Phys. Commun. 184, 2197 (2013). null null • null null null [[3]] G. Gaigalas, S. Fritzsche, Z. Rudzikas, Atomic Data and Nuclear null Data Tables null null 76, 235 (2000).

GRASP2018—A Fortran 95 version of the General Relativistic Atomic Structure Package