Development and use of quantum molecular models. 75. Comparative tests of theoretical procedures for studying chemical reactions

Dewar, Michael J. S.; Storch, Donn M.

doi:10.1021/ja00299a023

Cited by 283 publications

(117 citation statements)

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“…3 ab initio and semiempirical. Of these, ab Any semiempirical method is composed of initio, having no need for empirically detera theoretical framework and a set of paramemined parameters, is the more theoretically ters.…”

Section: Introductionmentioning

confidence: 99%

Optimization of parameters for semiempirical methods I. Method

1989

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A new method for obtaining optimized parameters for semiempirical methods has been developed and applied to the modified neglect of diatomic overlap (MNDO) method. The method uses derivatives of calculated values for properties with respect to adjustable parameters to obtain the optimized values of parameters. The large increase in speed is a result of using a simple series expression for calculated values of properties rather than employing full semiempirical calculations. With this optimization procedure, the rate‐determining step for parameterizing elements changes from the mechanics of parameterization to the assembling of experimental reference data.

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Section: Introductionmentioning

confidence: 99%

Optimization of parameters for semiempirical methods I. Method

1989

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“…Following suggestions from Dewar [9] and Delley [10], as further explored by Delley [11], and Grimme [12], Csonka, Ruzsinszky, Tao and Perdew [2] found that the MAE's of the atomization energies for functionals on all rungs of the ladder…”

Section: Atomization Energy Puzzlementioning

confidence: 92%

Why Density Functionals Should Not Be Judged Primarily by Atomization Energies

Perdew

Sun

Ruzsinszky

et al. 2016

Period. Polytech. Chem. Eng.

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Keywords density functional, atomization energy, electronic structure theory IntroductionThis year is the 50th anniversary of Kohn-Sham density functional theory [1], which from a humble beginning has grown up to be the most widely-used method of electronic structure calculation in condensed matter physics, quantum chemistry, and materials engineering. The popularity of this theory arises first because it is computationally efficient, with an orbital structure like that of Hartree or Hartree-Fock theory, and second because it is usefully accurate. There is an underlying exact theory for the ground-state energy and electron density, which inspires the continuing and successful (if slow) search for more accurate but still computationally tractable approximations to the needed density functional for the exchange-correlation energy. This is also the tenth anniversary of collaboration among the authors of this paper. In 2005, three of us (GIC, AR, JPP) published the first [2] of 35 collaborative research papers in density functional theory. (One year later, another of us (JS) started research in this theory as a graduate student with JPP.) That first collaborative paper raised questions about the atomization energies of molecules, which up to that time had been widely regarded as a "gold standard" of accuracy for density functional approximations. In 2015, when three of us (JS, AR, and JPP) have proposed what we regard as an optimally accurate functional that preserves computational efficiency [3], we return to the issue in the title of this article and present an explanation which is supported by numerical evidence at this high level of approximation.

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“…The calculation process of the molecular descriptors is described as below: All molecules were drawn into Hyperchem, and pre-optimized using MM+ molecular mechanics force field. A more precise optimization was done with semiempirical AM1 [10] method in MOPAC [11]. The molecular structures were optimized using the Polak-Ribiere algorithm until the root mean square gradient was 0.001.…”

Section: Methodsmentioning

confidence: 99%

Prediction of retention times for a large set of pesticides based on improved gene expression programming

Zhang

Sun

2008

Proceedings of the 10th Annual Conference on Genetic and Evolutionary Computation

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The purpose of the paper is to present a novel way to building Quantitative structure-retention relationship (QSRR) models. Studies was reported for predicting the retention times (RTs) of 110 pesticides which were detected by gas chromatography (GC) with mass selective detector (MSD). Chemical descriptors were calculated from the molecular structure of pesticides and the QSRR models of RTs with descriptors was built using the heuristic method (HM) and Improved Gene Expression Programming (IGEP), respectively. The obtained linear model of HM had a correlation

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Development and use of quantum molecular models. 75. Comparative tests of theoretical procedures for studying chemical reactions

Cited by 283 publications

References 0 publications

Optimization of parameters for semiempirical methods I. Method

Optimization of parameters for semiempirical methods I. Method

Why Density Functionals Should Not Be Judged Primarily by Atomization Energies

Prediction of retention times for a large set of pesticides based on improved gene expression programming

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