TY - JOUR

T1 - A parallel configuration interaction software package for high-precision atomic structure calculations

AU - Cheung, C.C.

AU - Kozlov , M.

AU - Porsev, S. G.

AU - Safronova, Marianna S

AU - Тупицын, Илья Игоревич

AU - Бондарев, Андрей Игоревич

PY - 2025/3/1

Y1 - 2025/3/1

N2 - We introduce the pCI software package for high-precision atomic structure calculations. The standard method of calculation is based on the configuration interaction (CI) method to describe valence correlations, but can be extended to attain better accuracy by including core correlations via many-body perturbation theory (CI+MBPT) or the all-order (CI+all-order) method. The software package enables calculations of atomic properties, including energy levels, g-factors, hyperfine structure constants, multipole transition matrix elements, polarizabilities, and isotope shifts. It also features modern high-performance computing paradigms, including dynamic memory allocations and large-scale parallelization via the message-passing interface, to optimize and accelerate computations. To improve accuracy of the calculations, we include a supplementary program package to calculate QED corrections via a variant of QEDMOD, as well as a package to include core correlations. Program summary: Program Title: pCI CPC Library link to program files: https://doi.org/10.17632/2kn5npnxj7.1 Developer's repository link: https://github.com/ud-pci/pCI Licensing provisions: GPLv3 Programming language: Fortran Supplementary material: Documentation available at https://pci.readthedocs.io Nature of problem: Calculation of atomic and ionic properties, including energy levels, hyperfine structure constants, multipole transition matrix elements, and polarizabilities. Solution method: The software package calculates energies and associated wave functions for the desired atomic states using the configuration interaction method. Using calculated wave functions, different atomic properties can be obtained, including g-factors, hyperfine structure constants, multipole transition amplitudes, polarizabilities, and others. Additional comments including restrictions and unusual features: All serial programs have been compiled and tested with the freely available Intel Fortran compilers “ifx” and “ifort”, and all parallel programs with the OpenMPI wrapper “mpifort” for Intel Fortran compilers. One-electron orbitals outside the nucleus are defined on the radial grid points. Inside the nucleus, they are described in a Taylor expansion over r/R, where R is the nuclear radius. This software package is not designed for calculations of high Rydberg states and continuous spectrum. The parallel programs are intended to be run on large computing clusters. References: [1] M.G. Kozlov et al., Comput. Phys. Commun. 195 (2015) 199.

AB - We introduce the pCI software package for high-precision atomic structure calculations. The standard method of calculation is based on the configuration interaction (CI) method to describe valence correlations, but can be extended to attain better accuracy by including core correlations via many-body perturbation theory (CI+MBPT) or the all-order (CI+all-order) method. The software package enables calculations of atomic properties, including energy levels, g-factors, hyperfine structure constants, multipole transition matrix elements, polarizabilities, and isotope shifts. It also features modern high-performance computing paradigms, including dynamic memory allocations and large-scale parallelization via the message-passing interface, to optimize and accelerate computations. To improve accuracy of the calculations, we include a supplementary program package to calculate QED corrections via a variant of QEDMOD, as well as a package to include core correlations. Program summary: Program Title: pCI CPC Library link to program files: https://doi.org/10.17632/2kn5npnxj7.1 Developer's repository link: https://github.com/ud-pci/pCI Licensing provisions: GPLv3 Programming language: Fortran Supplementary material: Documentation available at https://pci.readthedocs.io Nature of problem: Calculation of atomic and ionic properties, including energy levels, hyperfine structure constants, multipole transition matrix elements, and polarizabilities. Solution method: The software package calculates energies and associated wave functions for the desired atomic states using the configuration interaction method. Using calculated wave functions, different atomic properties can be obtained, including g-factors, hyperfine structure constants, multipole transition amplitudes, polarizabilities, and others. Additional comments including restrictions and unusual features: All serial programs have been compiled and tested with the freely available Intel Fortran compilers “ifx” and “ifort”, and all parallel programs with the OpenMPI wrapper “mpifort” for Intel Fortran compilers. One-electron orbitals outside the nucleus are defined on the radial grid points. Inside the nucleus, they are described in a Taylor expansion over r/R, where R is the nuclear radius. This software package is not designed for calculations of high Rydberg states and continuous spectrum. The parallel programs are intended to be run on large computing clusters. References: [1] M.G. Kozlov et al., Comput. Phys. Commun. 195 (2015) 199.

KW - Atomic structure

KW - Configuration interaction

KW - Coupled-cluster

KW - High-performance computing

KW - Isotope shifts

KW - Many-body perturbation theory

KW - Quantum electrodynamics

KW - Radiative transitions

UR - https://www.mendeley.com/catalogue/60a9e369-2fc0-3ed9-a1dc-2da21a74d116/

U2 - 10.1016/j.cpc.2024.109463

DO - 10.1016/j.cpc.2024.109463

M3 - Article

VL - 308

JO - Computer Physics Communications

JF - Computer Physics Communications

SN - 0010-4655

M1 - 109463

ER -