Group theoretical selection rules for the transition states of chemical reactions

Stanton, Richard; McIver, James

doi:10.1021/ja00846a012

Cited by 166 publications

(51 citation statements)

References 5 publications

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“…At large distances, the bottom of the thalweg corresponds to an eclipsed conformation (symmetry D3h). According to the symmetry rules [96], the IRC must lead to the eclipsed ethane (&), which is the transition state between two equivalent staggered conformations (OM). Thus, the IRC has to follow a ridge and any distortion to the D3h symmetry along the integrated path will reflect the lack of accuracy of the numerical integrator.…”

Section: Steepest Descent Paths and The Intrinsic Reaction Coordinatementioning

confidence: 99%

Algorithmic tools in the study of semiempirical potential surfaces

Liotard

1992

Int J of Quantum Chemistry

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The most efficient optimization methods implemented in the semiempirical package AMPAC are presented. They concern the minimization of the energy or of the gradient norm by either pseudo-Newton or quadratic procedures, the search for transition states, and the intrinsic reaction coordinate in conjunction with variational transition-state theories. Nonlocal methods such as simulated annealing are also introduced. 0 1992 John Wiley & Sons, Inc.

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Section: Steepest Descent Paths and The Intrinsic Reaction Coordinatementioning

confidence: 99%

Algorithmic tools in the study of semiempirical potential surfaces

Liotard

1992

Int J of Quantum Chemistry

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“…These authors also discuss coordinate transformations, particularly to the Hessian eigenvalue representation. It has previously been suggested that non-unitary transformations to internal coordinates do not preserve the Hessian eigenvalues and eigenvectors [10]. However, this problem can be dealt with by defining the gradient and Hessian so that they transform like first and second rank covariant tensors, respectively.…”

Section: Introductionmentioning

confidence: 99%

Comparison of reaction pathways calculated by different algorithms for disilane and water trimer

Walsh¹,

Wales²

1997

Z Phys D

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There still exists some confusion in the literature concerning the definition of a minimum energy pathway and the coordinate system in which it is calculated. Here we compare steepest-descent and eigenvector-following pathways, both with and without a mass-weighted metric. The systems studied are disilane and the water trimer, and we employ various basis sets at the SCF level of theory. We find that paths calculated using eigenvector-following and steepestdescent are practically the same, at least in terms of the reaction mechanism. We find that for the mass-weighted metric the pathways are similar, although in principle they do not have to be identical. Finally, we verify that the geometrical symmetry selection rules hold for a pathway mediated by a recently discovered transition state of the disilane system.

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“…[1][2][3][4][5][6][7][8][9]. Whereas the early studies focussed on individual nuclear configurations or on specific reaction paths, in a recent study some new results have been derived using a global approach and a symmetry domain partitioning of the nuclear configuration space (10).…”

Section: Introductionmentioning

confidence: 99%

“…Note that C(h,i) and B(C(h,i), r) are within the same relaxed cross section C,, of the nuclear configuration space M. Consequently, a path of steepest descent from K must stay within C,,, and hence it cannot avoid passing through the sphere S(C(h,i), r). Also note that, due to condition [4] and to the positivity of r , point K' of the boundary sphere S(C(h,i), r ) cannot be a critical point. Consequently, by the preservation of point symmetry elements along steepest descent paths, sphere S(C(h,i), r) must have a point K' with precisely the same point symmetry elements as K.…”

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confidence: 99%

On the allowed symmetries of all distorted forms of conformers, molecules, and transition structures

Mezey¹

1992

Can. J. Chem.

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T1li.s p.pc11)er is derlicclrc~cl m Prof.pc>ssor. Sigerli H~izirlngn or1 rl~e occnsiorc of' his 65th Oir-thclcly PAUL G. MEZEY. Can. J. Chem. 70. 343 (1992). Based on the catchment region point symmetry theorem, a general framework and some new results are presented on symmetry constraints of deformations preserving chemical identity. The point symmetries of the unique critical point (equilibrium) nuclear arrangement corresponding to a conformer, molecule, or a transition structure and those of a family of nuclear arrangements with an arbitrarily small limit on the allowed distortions provide a complete symmetry characterization of the entire potential surface catchment region of the chemical species. Consequently, the point symmetries of all distorted molecular forms that preserve chemical identity can be deduced by testing symmetry conditions only within an arbitrarily small domain of the potential surface, in the vicinity of the equilibrium arrangement. Additional constraints are deduced on the point symmetries of transition structures obtained directly from the given conformer.Kej~ n,or.ds: molecular distortions, symmetry, catchment regions, new symmetry theorems, framework groups, point groups.PAUL. G. MEZEY. Can. J. Chem. 70, 343 (1992). En se basant sur le theorkme de la symetrie du point dans la region de captation, on prtsente un cadre general et quelques nouveaux resultats relatifs j. la symCtrie des contraintes de deformation qui preservent I'identite chimique. Les symetries de point du point critique unique (Cquilibre) de I'arrangement nucleaire correspondant 5 un conformere, la molCcule ou la structure de transition et celles d'une famille d'arrangements nucleaires, avec une faible tolerance arbitraire pour les distorsions permises, fournissent une caracterisation complkte de la symCtrie de toute la surface de potentie1 de la region de captation des espkces chimiques. En vkrifiant les conditions de symetrie uniquement a l'intkrieur du faible dornaine arbitraire de la surface de potentiel au voisinage de I'arrangement B I'Cquilibre, on peut alors deduire les symetries de point de toutes les formes molCculaires dCformCes qui preservent I'identitC chirnique. On deduit des contraintes additionnelles sur les symetries de point des structures de transition obtenues directement a' partir du conformkre donne.Mors c l b : distorsions molCculaires, symetrie, regions de captation, nouveaux thkorkmes de la symttrie, cadre general, groupes de point.[Traduit par la rtdaction]

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Group theoretical selection rules for the transition states of chemical reactions

Cited by 166 publications

References 5 publications

Algorithmic tools in the study of semiempirical potential surfaces

Algorithmic tools in the study of semiempirical potential surfaces

Comparison of reaction pathways calculated by different algorithms for disilane and water trimer

On the allowed symmetries of all distorted forms of conformers, molecules, and transition structures

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