- Email: [email protected]
Third version of a program for calculating the static interaction potential between an electron and a diatomic molecule
C-635 Computer Physics Communications 20 (1980) 267-274 © North-Holland Publishing Company
T H I R D V E R S I O N O F A P R O G R A M F O R C A L C U L A T I N G THE S T A T I C I N T E R A C T I O N P O T E N T I A L BETWEEN AN E L E C T R O N A N D A D I A T O M I C M O L E C U L E G. R A S E E V *
Centre de M~canique Ondulatoire Appliqu~e, 23. rue du Maroc, 75019 Paris, France Received 23 May 1979
PROGRAM SUMMARY
Title o f program: ONE CENTRE STATIC POTENTIAL Catalogue number ACZR Computer: IBM 370• 168; blstallation: Centre Inter Regional de Calcul Electronique, Baitiment 506, Campus d'Orsay, 91405 Orsay, France and Computer: IBM 370/158;Installation: Universit~ de Liege, Belgium Operating system: JES 3 Program language: FORTRAN IV High speed storage required: 475 Kwords Number o f bits in a word: 32 Overlay structure: none Number o f files requested: 2 or 3 Other peripherals used: card reader, card punch, line printer Number o f cards in combined program and test deck: 2375
Reference to other published version o f this program: Catalogue number: ACQW; 7~tle: STATIC INTERACTION POTENTIAL;Ref. in CPC: 2 (1971), 261 and ACWO; 7~'tle: OCEP W.F. and STATIC POTENTIAL; Re]:. in CPC: 11(1976) 237
Method o f solution The original two-centre wave function is assumed to have a closed or restricted open-shell representation from a LCAOMO-SCF calculation. The LCAO basis is of Slater-type centered on the two nuclei of the molecule: The atomic orbitals are expanded in Legrendre polynomials around either the centre of mass, or the centre of charge or one of the two atoms. The resulting wave function once orthonormalised by the symmetric orthonormalisation of Lowdin is used for calculating the static potential.
Restrictions on the complexity o f the problem This program is partially dynamically allocated either through an IBM 370/165 assembler subroutine or a main FORTRAN program (present version). The only restrictions are given below. Maximum number of basis functions is 50; the one centre expansion of the potential is limited to a maximum of 21 terms and the expansion of the molecular orbital is limited to 20 terms.
Keywords: quantum chemistry, single-centre expansion, static potential, dipole moment, quadrupole moment, multipole expansions, electron scattering
Nature o f the physical problem This program calculates the one-centre expansion of a twocentre wave function of a diatonic molecule and also the multipole expansion of its static interaction with a point charge. It is an extension to some classes of open-shell targets of the previous versions [ 1,21 and it provides both the wave function and the potential in a form suitable for use in an electron-molecule scattering program [ 3 ].
Typical running time For 200 mesh points, 21 atomic and 4 molecular orbitrals, 15 terms in the expansion of the one-centre molecular orbital and 4 terms in the expansion of the static potential the program takes 42 s on an IBM 370[168.
References [ 1 ] F.H.M. Faisal and A.L.V. Tench, Comput. Phys. Commun. 2 (1971) 261. [21 F.A. Gianturco, Comput. Phys. Commun. 11 (1976) 237. [3] G. Ra~eev, Comput. Phys. Commun. 20 (1980) 275.
* Present address: Laboratoire de Chimie C,dn6rale et Physique Bfftiment B.6 - Universit6 de Libge, B-4000 Sart Tilman per Libge 1, Belgium.
T H I R D V E R S I O N O F A P R O G R A M F O R C A L C U L A T I N G THE S T A T I C I N T E R A C T I O N P O T E N T I A L BETWEEN AN E L E C T R O N A N D A D I A T O M I C M O L E C U L E G. R A S E E V *
Centre de M~canique Ondulatoire Appliqu~e, 23. rue du Maroc, 75019 Paris, France Received 23 May 1979
PROGRAM SUMMARY
Title o f program: ONE CENTRE STATIC POTENTIAL Catalogue number ACZR Computer: IBM 370• 168; blstallation: Centre Inter Regional de Calcul Electronique, Baitiment 506, Campus d'Orsay, 91405 Orsay, France and Computer: IBM 370/158;Installation: Universit~ de Liege, Belgium Operating system: JES 3 Program language: FORTRAN IV High speed storage required: 475 Kwords Number o f bits in a word: 32 Overlay structure: none Number o f files requested: 2 or 3 Other peripherals used: card reader, card punch, line printer Number o f cards in combined program and test deck: 2375
Reference to other published version o f this program: Catalogue number: ACQW; 7~tle: STATIC INTERACTION POTENTIAL;Ref. in CPC: 2 (1971), 261 and ACWO; 7~'tle: OCEP W.F. and STATIC POTENTIAL; Re]:. in CPC: 11(1976) 237
Method o f solution The original two-centre wave function is assumed to have a closed or restricted open-shell representation from a LCAOMO-SCF calculation. The LCAO basis is of Slater-type centered on the two nuclei of the molecule: The atomic orbitals are expanded in Legrendre polynomials around either the centre of mass, or the centre of charge or one of the two atoms. The resulting wave function once orthonormalised by the symmetric orthonormalisation of Lowdin is used for calculating the static potential.
Restrictions on the complexity o f the problem This program is partially dynamically allocated either through an IBM 370/165 assembler subroutine or a main FORTRAN program (present version). The only restrictions are given below. Maximum number of basis functions is 50; the one centre expansion of the potential is limited to a maximum of 21 terms and the expansion of the molecular orbital is limited to 20 terms.
Keywords: quantum chemistry, single-centre expansion, static potential, dipole moment, quadrupole moment, multipole expansions, electron scattering
Nature o f the physical problem This program calculates the one-centre expansion of a twocentre wave function of a diatonic molecule and also the multipole expansion of its static interaction with a point charge. It is an extension to some classes of open-shell targets of the previous versions [ 1,21 and it provides both the wave function and the potential in a form suitable for use in an electron-molecule scattering program [ 3 ].
Typical running time For 200 mesh points, 21 atomic and 4 molecular orbitrals, 15 terms in the expansion of the one-centre molecular orbital and 4 terms in the expansion of the static potential the program takes 42 s on an IBM 370[168.
References [ 1 ] F.H.M. Faisal and A.L.V. Tench, Comput. Phys. Commun. 2 (1971) 261. [21 F.A. Gianturco, Comput. Phys. Commun. 11 (1976) 237. [3] G. Ra~eev, Comput. Phys. Commun. 20 (1980) 275.
* Present address: Laboratoire de Chimie C,dn6rale et Physique Bfftiment B.6 - Universit6 de Libge, B-4000 Sart Tilman per Libge 1, Belgium.