- 作者：A. Borgoo ; O. Scharf ; G. Gaigalas ; M. Godefroid
- 关键词：Electron density ; Density matrix ; Natural orbitals ; Multiconfiguration wave functions
- 刊名：Computer Physics Communications
- 出版年：2010
- 出版时间：February 2010
- 年：2010
- 卷：181
- 期：2
- 页码：426-439
- 全文大小：360 K
Program summary
Program title: DENSITY
Catalogue identifier: AEFR_v1_0
Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEFR_v1_0.html
Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland
Licensing provisions: Standard CPC license, http://cpc.cs.qub.ac.uk/licence/licence.html
No. of lines in distributed program, including test data, etc.: 6603
No. of bytes in distributed program, including test data, etc.: 169 881
Distribution format: tar.gz
Programming language: FORTRAN 90
Computer: HP XC Cluster Platform 4000
Operating system: HP XC System Software 3.2.1, which is a Linux distribution compatible with Red Hat Enterprise Advanced Server
Word size: 32 bits
Classification: 2.1, 2.9, 4.1
Subprograms used:
Nature of problem: This program determines the atomic electronic density in the MCHF (LS) or Breit–Pauli (LS J) approximation. It also evaluates the natural orbitals by diagonalizing the density matrix.
Solution method: Building the density operator using second quantization – spherical symmetry averaging – evaluating the matrix elements of the one-body excitation operators in the configuration state function (CSF) space using the angular momentum theory in orbital, spin, and quasispin spaces.
Restrictions: Original restrictions from ATSP2K package, i.e. all orbitals within a wave function expansion are assumed to be orthonormal. Configuration states are restricted to at most eight subshells in addition to the closed shells common to all configuration states. The maximum size of the working arrays, related to the number of CSFs and active orbitals, is limited by the available memory and disk space.
Unusual features: The programming style is essentially F77 with extensions for the POINTER data type and associated memory allocation. These have been available on workstations for more than a decade, but their implementations are compiler dependent. The present code has been installed and tested extensively using the Portland Group, pgf90, compiler.
Running time: The calculation of the electron density for an n=9 complete active space (CAS) MCHF wave function (271 733 CSFs – 45 orbitals) takes around 9 minutes on one AMD Opteron dual-core at 2.4 GHz CPU.
References:
[1] C. Froese Fischer, G. Tachiev, G. Gaigalas, M.R. Godefroid, An MCHF atomic-structure package for large-scale calculation, Comput. Phys. Commun. 176 (2007) 559–579.