On the link atom distance in the ONIOM scheme. An harmonic approximation analysis

Derat, Étienne; Bouquant, James; Humbel, Stéphane

doi:10.1016/s0166-1280(03)00288-4

Cited by 23 publications

(15 citation statements)

References 23 publications

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“…Even for the clearly unreasonable choices, like g ϭ 0.3 or g ϭ 0.8, the results differ at the most by 2 kJ mol Ϫ1 , compared to the calculations with the standard value of the distance parameter. This finding is consistent with other reported QM/QM ONIOM results obtained, however, for rather small systems [7,13], indicating that reaction energies are almost insensitive on the link atom distance.…”

Section: Link Atom Distancesupporting

confidence: 93%

“…In principle, the link atom distance influences the results obtained within the framework of the ONIOM methodology [7,13]. During the calculations, this distance is determined by the scale factor g. Here, the standard g value from the Gaussian code is 0.5289, defined as a typical OOH bond length divided by a typical OOSi bond length [7].…”

Section: Link Atom Distancementioning

confidence: 99%

“…Generally, the reasonable value of the g factor can be obtained by dividing the typical AOH bond length by the typical AOB bond length. The optimal scale factor depends on the theoretical methods employed for the description of both layers [7,13]. Catalytic olefin metathesis is a reversible scission and recombination of carbon-carbon double bonds (Scheme 1).…”

Section: Introductionmentioning

confidence: 99%

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Application of the ONIOM (QM/QM) method in the study of molybdena–silica system active in olefin metathesis

Handzlik

2007

Int J of Quantum Chemistry

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ABSTRACT:The two-layer ONIOM method is applied for description of Momethylidene center on silica, which is the active site of olefin metathesis. Two clusters of different size are employed to model the silica surface. For the larger one, two differently defined inner layers (the model systems) are tested. In all the calculations, the B3LYP functional is adopted for the inner layer, while the Hartree-Fock method or the local density approximation (SVWN5 functional) is used for the treatment of the real system. Based on the reference results obtained for the real system from the B3LYP calculations, it is concluded that both B3LYP:HF and B3LYP:SVWN5 schemes are suitable for proper description of the geometry of the Mo center and its activity in ethene metathesis. The former combination is a little better choice, however. It is also shown that the inner layer, including the third coordination sphere of molybdenum, is large enough to obtain satisfactory results. On the other hand, the relative energies and some geometrical parameters of the active site are dependent on the size of the entire system studied. The sensitivity of the geometrical parameters and reaction energies to the changes of the scale factor g, involved in the ONIOM scheme, is studied as well. It is concluded that the link atom distance is not crucial for obtaining correct results.

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Section: Link Atom Distancesupporting

confidence: 93%

Section: Link Atom Distancementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Application of the ONIOM (QM/QM) method in the study of molybdena–silica system active in olefin metathesis

Handzlik

2007

Int J of Quantum Chemistry

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“…The exact value of the scale factor has a very little effect on the absolute ONIOM energy and even less on geometry optimizations. 35 There are simple rules that should be followed in the definition of the model system. The cuts should be made on single, nonpolar, and nonconstrained bonds.…”

Section: Theory and Methodsmentioning

confidence: 99%

Using the ONIOM hybrid method to apply equation of motion CCSD to larger systems: Benchmarking and comparison with time-dependent density functional theory, configuration interaction singles, and time-dependent Hartree–Fock

Caricato

Vreven

Trucks

et al. 2009

The Journal of Chemical Physics

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Assessment of time-dependent density functional schemes for computing the oscillator strengths of benzene, phenol, aniline, and fluorobenzene J. Chem. Phys. 127, 084103 (2007) Equation of motion coupled-cluster singles and doubles ͑EOM-CCSD͒ is one of the most accurate computational methods for the description of one-electron vertical transitions. However, its O͑N 6 ͒ scaling, where N is the number of basis functions, often makes the study of molecules larger than 10-15 heavy atoms prohibitive. In this work we investigate how accurately less expensive methods can approximate the EOM-CCSD results. We focus on our own N-layer integrated molecular orbital molecular mechanics ͑ONIOM͒ hybrid scheme, where the system is partitioned into regions which are treated with different levels of theory. For our set of benchmark calculations, the comparison of conventional configuration interaction singles ͑CIS͒, time-dependent Hartree-Fock ͑TDHF͒, and time-dependent density functional theory ͑TDDFT͒ methods and ONIOM ͑with different low level methods͒ showed that the best accuracy-computational time combination is obtained with ONIOM͑EOM:TDDFT͒, which has a rms of the error with respect to the conventional EOM-CCSD of 0.06 eV, compared with 0.47 eV of the conventional TDDFT.

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“…For ground state calculations, there are simple guidelines that should be followed in the definition of the model system, 13 for example, the cuts should be made on single, nonpolar, and nonconstrained bonds; an atom in the low level layer should not be bonded to two or more atoms in the high level layer. A study by Derat et al 27 showed that the exact value of the link atom bond length has a very small effect on the absolute ONIOM energy and an even smaller effect on optimized geometries. The aim of this work is thus to extend the investigations in Refs.…”

Section: Introductionmentioning

confidence: 99%

Link atom bond length effect in ONIOM excited state calculations

Caricato¹,

Vreven²,

Trucks³

et al. 2010

The Journal of Chemical Physics

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Articles you may be interested inAccurate rotational constant and bond lengths of hexafluorobenzene by femtosecond rotational Raman coherence spectroscopy and ab initio calculations J. Chem. Phys. 141, 194303 (2014) We investigate how the choice of the link atom bond length affects an electronic transition energy calculation with the so-called our own N-layer integrated molecular orbital molecular mechanics ͑ONIOM͒ hybrid method. This follows our previous paper ͓M. Caricato et al., J. Chem. Phys. 131, 134105 ͑2009͔͒, where we showed that ONIOM is able to accurately approximate electronic transition energies computed at a high level of theory such as the equation of motion coupled cluster singles and doubles ͑EOM-CCSD͒ method. In this study we show that the same guidelines used in ONIOM ground state calculations can also be followed in excited state calculations, and that the link atom bond length has little effect on the ONIOM energy when a sensible model system is chosen. We also suggest further guidelines for excited state calculations which can help in checking the effectiveness of the definition of the model system and controlling the noise in the calculation.

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On the link atom distance in the ONIOM scheme. An harmonic approximation analysis

Cited by 23 publications

References 23 publications

Application of the ONIOM (QM/QM) method in the study of molybdena–silica system active in olefin metathesis

Application of the ONIOM (QM/QM) method in the study of molybdena–silica system active in olefin metathesis

Using the ONIOM hybrid method to apply equation of motion CCSD to larger systems: Benchmarking and comparison with time-dependent density functional theory, configuration interaction singles, and time-dependent Hartree–Fock

Link atom bond length effect in ONIOM excited state calculations

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