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A new module for constrained multi-fragment geometry optimization in internal coordinates implemented in the MOLCAS package.

Vysotskiy, Victor LU ; Boström, Jonas LU and Veryazov, Valera LU orcid (2013) In Journal of Computational Chemistry 34(30). p.2657-2665
Abstract
A parallel procedure for an effective optimization of relative position and orientation between two or more fragments has been implemented in the MOLCAS program package. By design, the procedure does not perturb the electronic structure of a system under the study. The original composite system is divided into frozen fragments and internal coordinates linking those fragments are the only optimized parameters. The procedure is capable to handle fully independent (no border atoms) fragments as well as fragments connected by covalent bonds. In the framework of the procedure, the optimization of relative position and orientation of the fragments are carried out in the internal "Z-matrix" coordinates using numerical derivatives. The total... (More)
A parallel procedure for an effective optimization of relative position and orientation between two or more fragments has been implemented in the MOLCAS program package. By design, the procedure does not perturb the electronic structure of a system under the study. The original composite system is divided into frozen fragments and internal coordinates linking those fragments are the only optimized parameters. The procedure is capable to handle fully independent (no border atoms) fragments as well as fragments connected by covalent bonds. In the framework of the procedure, the optimization of relative position and orientation of the fragments are carried out in the internal "Z-matrix" coordinates using numerical derivatives. The total number of required single points energy evaluations scales with the number of fragments rather than with the total number of atoms in the system. The accuracy and the performance of the procedure have been studied by test calculations for a representative set of two- and three-fragment molecules with artificially distorted structures. The developed approach exhibits robust and smooth convergence to the reference optimal structures. As only a few internal coordinates are varied during the procedure, the proposed constrained fragment geometry optimization can be afforded even for high level ab initio methods like CCSD(T) and CASPT2. This capability has been demonstrated by applying the method to two larger cases, CCSD(T) and CASPT2 calculations on a positively charged benzene lithium complex and on the oxygen molecule interacting to iron porphyrin molecule, respectively. © 2013 Wiley Periodicals, Inc. (Less)
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author
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type
Contribution to journal
publication status
published
subject
in
Journal of Computational Chemistry
volume
34
issue
30
pages
2657 - 2665
publisher
John Wiley & Sons Inc.
external identifiers
  • wos:000325540200008
  • pmid:24006272
  • scopus:84885630229
ISSN
1096-987X
DOI
10.1002/jcc.23428
language
English
LU publication?
yes
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The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Theoretical Chemistry (S) (011001039)
id
b6405f74-66fb-49d4-89c8-b2556bc70b91 (old id 4066271)
date added to LUP
2016-04-01 10:04:49
date last changed
2023-01-02 00:52:35
@article{b6405f74-66fb-49d4-89c8-b2556bc70b91,
  abstract     = {{A parallel procedure for an effective optimization of relative position and orientation between two or more fragments has been implemented in the MOLCAS program package. By design, the procedure does not perturb the electronic structure of a system under the study. The original composite system is divided into frozen fragments and internal coordinates linking those fragments are the only optimized parameters. The procedure is capable to handle fully independent (no border atoms) fragments as well as fragments connected by covalent bonds. In the framework of the procedure, the optimization of relative position and orientation of the fragments are carried out in the internal "Z-matrix" coordinates using numerical derivatives. The total number of required single points energy evaluations scales with the number of fragments rather than with the total number of atoms in the system. The accuracy and the performance of the procedure have been studied by test calculations for a representative set of two- and three-fragment molecules with artificially distorted structures. The developed approach exhibits robust and smooth convergence to the reference optimal structures. As only a few internal coordinates are varied during the procedure, the proposed constrained fragment geometry optimization can be afforded even for high level ab initio methods like CCSD(T) and CASPT2. This capability has been demonstrated by applying the method to two larger cases, CCSD(T) and CASPT2 calculations on a positively charged benzene lithium complex and on the oxygen molecule interacting to iron porphyrin molecule, respectively. © 2013 Wiley Periodicals, Inc.}},
  author       = {{Vysotskiy, Victor and Boström, Jonas and Veryazov, Valera}},
  issn         = {{1096-987X}},
  language     = {{eng}},
  number       = {{30}},
  pages        = {{2657--2665}},
  publisher    = {{John Wiley & Sons Inc.}},
  series       = {{Journal of Computational Chemistry}},
  title        = {{A new module for constrained multi-fragment geometry optimization in internal coordinates implemented in the MOLCAS package.}},
  url          = {{http://dx.doi.org/10.1002/jcc.23428}},
  doi          = {{10.1002/jcc.23428}},
  volume       = {{34}},
  year         = {{2013}},
}