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III. A force constant adjuster program to obtain least squares fit to observed frequencies of molecules and crystals
C-464 Computer Physics Communications 14 (1978) 245-254 © North-Holland Publishing Company
III. A F O R C E C O N S T A N T A D J U S T E R P R O G R A M TO O B T A I N L E A S T S Q U A R E S F I T TO O B S E R V E D F R E Q U E N C I E S O F M O L E C U L E S A N D C R Y S T A L S F l e m m i n g Yssing H A N S E N
Fysisk-Kemisk Institut, The technical Universio, of Denmark, DK 2800 Lyngby. Denmark Received 21 July 1977 Revised manuscript received 12 December 1977
PROGRAM SUMMARY
Title o/program : FYADJ Catalogue number: ACXS
tion of molecules or crystals in the harmonic approximation, in such a way as to give a least squares fit of calculated frequencies to observed frequencies.
Computer: IBM 370/165 Installation: NEUCC, The Technical
Method of solu tion
University of Denmark
The calculations with this program are based on the results of the FYFRE program described in part I1, where data for the generation of the analytic form of the dynamical matrix in terms of relevant force constants have been obtained. The eigenvalues of the Hermitian matrix, which has been blocked diago~alized by symmetry coordinate matrices, are calculated and compared with observed frequencies. An iterative determination of the force constants are performed using a procedure, where only the calculated frequencies need to be entered, while derivatives of the frequencies with respect to force constants do not have to be entered.
Operating System: OS/MVT, Release 21.7 Program language used: FORTRAN IV High speed storage required: 47500 words No. of bits in a word: 32 Overlay structure: none No. o/magnetic tapes required: none Other peripherals used: card reader, line printer, magnetic disc (2 files)
No. of cards in combined program and test deck: 848
Typical running time The running time obviously depends in particular on the number of iterations to be performed and to a lesser degree on the nature of the problem. For the test example considered here the running time for 10 iterations were 12 s including compilation time. The compilation time for the program is 7 s.
CPC Library subprograms used:
Unusual features of the program
Cat. No.
?~tle
R e / i n CPC
ACXQ ACXR
FYCOOR FYFRE
This issue This issue
The storage requirement depends on the problem, that is the number of normal modes, and the number of non zero elements of the dynamical matrix. In the present set up the storage requirement is set to 47500 words. Problems with up to 30 normal modes and 500 non zero matrix elements may be considered, while up to 10 force constants may be determined simultaneously in one calculation and up to 100 experimental frequencies may be considered. One should consult the long write up for details.
Nature of physical problem The objective of the present program is to determine the values of a given set of force constants for the internal vibra-
Restrictions on the complexity of the problem The only restriction of the program is the high speed storage available.
III. A F O R C E C O N S T A N T A D J U S T E R P R O G R A M TO O B T A I N L E A S T S Q U A R E S F I T TO O B S E R V E D F R E Q U E N C I E S O F M O L E C U L E S A N D C R Y S T A L S F l e m m i n g Yssing H A N S E N
Fysisk-Kemisk Institut, The technical Universio, of Denmark, DK 2800 Lyngby. Denmark Received 21 July 1977 Revised manuscript received 12 December 1977
PROGRAM SUMMARY
Title o/program : FYADJ Catalogue number: ACXS
tion of molecules or crystals in the harmonic approximation, in such a way as to give a least squares fit of calculated frequencies to observed frequencies.
Computer: IBM 370/165 Installation: NEUCC, The Technical
Method of solu tion
University of Denmark
The calculations with this program are based on the results of the FYFRE program described in part I1, where data for the generation of the analytic form of the dynamical matrix in terms of relevant force constants have been obtained. The eigenvalues of the Hermitian matrix, which has been blocked diago~alized by symmetry coordinate matrices, are calculated and compared with observed frequencies. An iterative determination of the force constants are performed using a procedure, where only the calculated frequencies need to be entered, while derivatives of the frequencies with respect to force constants do not have to be entered.
Operating System: OS/MVT, Release 21.7 Program language used: FORTRAN IV High speed storage required: 47500 words No. of bits in a word: 32 Overlay structure: none No. o/magnetic tapes required: none Other peripherals used: card reader, line printer, magnetic disc (2 files)
No. of cards in combined program and test deck: 848
Typical running time The running time obviously depends in particular on the number of iterations to be performed and to a lesser degree on the nature of the problem. For the test example considered here the running time for 10 iterations were 12 s including compilation time. The compilation time for the program is 7 s.
CPC Library subprograms used:
Unusual features of the program
Cat. No.
?~tle
R e / i n CPC
ACXQ ACXR
FYCOOR FYFRE
This issue This issue
The storage requirement depends on the problem, that is the number of normal modes, and the number of non zero elements of the dynamical matrix. In the present set up the storage requirement is set to 47500 words. Problems with up to 30 normal modes and 500 non zero matrix elements may be considered, while up to 10 force constants may be determined simultaneously in one calculation and up to 100 experimental frequencies may be considered. One should consult the long write up for details.
Nature of physical problem The objective of the present program is to determine the values of a given set of force constants for the internal vibra-
Restrictions on the complexity of the problem The only restriction of the program is the high speed storage available.