Programs in Physics & Physical Chemistry
|[Licence| Download | New Version Template] adoo_v2_0.tar.gz(3552 Kbytes)|
|Manuscript Title: Pure spin-angular momentum coefficients for non-scalar one-particle operators in jj-coupling.|
|Authors: G. Gaigalas, S. Fritzsche|
|Program title: ANCO(2)|
|Catalogue identifier: ADOO_v2_0|
Distribution format: tar.gz
|Journal reference: Comput. Phys. Commun. 148(2002)349|
|Programming language: Fortran.|
|Computer: IBM RS 6000, PC Pentium II, AMD Athlon K7.|
|Operating system: IBM AIX 6.2.2+, Linux 7.1.|
|RAM: 200K words|
|Word size: 32|
|Keywords: Atomic many-body perturbation theory, Complex atom, Configuration interaction, Effective Hamiltonian, Multiconfiguration Dirac-Fock, Photoionization, Racah algebra, Reduced matrix element, Relativistic, Second quantization, Spin-angular coefficients, Tensor operators, Transition probabilities, 9/2-subshell, Atomic physics, Structure.|
Nature of problem:
The matrix elements of a one-electron tensor operator A^**k of (any) rank k with respect to a set of configuration state functions (CSF) |gammaiJiPi> can be written as Sigmaij(tij**k(ab)(a|A^**k|b)) where the spin-angular coefficients tij**k(ab) are independent of the operator A^**k; i, j are CSF labels and a, b specify the interacting orbitals. A combination of second-quantization and quasispin methods has been utilized in order to derive and to obtain these angular coefficients for one-electron tensor operator of any rank . Operators of non-scalar rank, k>0, occur frequently, for instance, in the study of transition probabilities, photoionization and electron capture processes, alignment transfer, collision strengths, and elsewhere.
Reasons for new version:
The RATIP package  has been found an efficient tool during recent years, in order to exploit the (relativistic atomic) wave functions from the GRASP92 program  for the computation of atomic properties and processes. Apart from a more efficient set-up of the (Dirac-Coulomb-Breit) Hamiltonian matrix , the RATIP program now supports large-scale computations of transition probabilities within a relaxed orbital basis , Auger rates and angular anisotropy parameters , and of several other quantities. For these properties, the spin-angular coefficients for scalar one- and two- particle operators are sufficient, as are obtained from the previous version of ANCO . However, in order to extend the range of (possible) applications also to other processes such as the atomic photoionization, (radiative) electron capture, or photoexcitation and alignment studies, non-scalar one-particle operators will occur and need to be treated efficiently. With the presently revised version of ANCO, we provide the spin-angular coefficients for such operators, making use of the modern design of the RATIP package in Fortran 90/95 . Similarly as for all previously implemented components of this package, the revised ANCO program facilitates the use of large wave function expansions of several ten thousand CSF or even more in the future.
Summary of revisions:
When compared with the previous CPC version of the ANCO program , the following modifications and (new) capabilities have been added:
For all subshells with j>=11/2 (i.e. h11/2-, i-, ... electrons), the maximal number of equivalent electrons is restricted to two.
ANCO has been designed as component of the RATIP package  for calculating a variety of relativistic atomic transition and ionization properties. Owing to the careful use of allocatable and pointer arrays, there is (almost) no restriction of the size or any dimension of the the "physical problem" apart from the computer resources themselves.
Number of bits in a word: All real variables are parameterized by a selected kind parameter. Currently this parameter is set to double precision (two 32-bit words) for consistency with other components of the RATIP package .
New version: The new version supersedes the previous one. Apart from scalar one- and two-particle tensor operators, the program now supports also non-scalar one-particle operators a^**k for any rank k>0.
This strongly depends on the system and the size of the wave function expansion to be considered. Our test case, which is distributed with the code in the subdirectory test-anco, required 32 s on a 1400 MHz AMD Athlon K7/1400T. Typically, ANCO calculates about 10,000 angular coefficients per second.
|||G. Gaigalas, S. Fritzsche, I.P. Grant, Comput. Phys. Comm. 139 (2001) 263.|
|||S. Fritzsche, J. Elec. Spec. Rel. Phen. 114-116 (2001) 1155.|
|||G. Gaigalas, Lithuanian Phys. J. 39 (1999) 63.|
|||F.A. Parpia, C.F. Fischer, I.P. Grant, Comput. Phys. Comm. 94 (1996) 249.|
|||S. Fritzsche, C.F. Fischer, G. Gaigalas, Comput. Phys. Comm (2002), in print.|
|||S. Fritzsche, C.F. Fischer, C.Z. Dong, Comput. Phys. Comm. 124 (2000) 343.|
|||K. Ueda, Y. Shimizu, H. Chiba, M. Kitajima, H. Tanaka, S. Fritzsche, N.M. Kabachnik, J. Phys. B 34 (2001) 107.|
|||M. Metcalf, J. Reid, Fortran 90/95 Explained, Oxford University Press, 1996.|
|||G. Gaigalas, Z. Rudzikas, C.F. Fischer, J. Phys. B 30 (1997) 3747.|
|Disclaimer | ScienceDirect | CPC Journal | CPC | QUB|