Analytic gradients for the multicentred integrated QM:QM method for weakly bound clusters: efficient and accurate 2-body:many-body geometry optimizations

ElSohly, Adel M.; Shaw, Cynthia L.; Guice, Marlo E.; Smith, Brittney D.; Tschumper, Gregory S.

doi:10.1080/00268970701633126

Cited by 33 publications

(34 citation statements)

References 27 publications

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“…Analytic gradients, for example, have been implemented for N-body:Many-body QM:QM method and applied to water and other hydrogen-bonded clusters. 234,236 In a study of more than 70 water clusters, two-body:many-body optimizations with MP2 as the high-level method and HF as the low-level method (MP2:HF) yielded structures nearly identical to those from the conventional MP2 calculation with the haTZ basis set.…”

Section: Strategies For Extending High-accuracy Methods To Larger Clumentioning

confidence: 81%

Wavefunction methods for the accurate characterization of water clusters

Howard

Tschumper

2013

WIREs Comput Mol Sci

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Although the first ab initio Hartree-Fock computations of the water dimer were reported more than four decades ago, the detailed characterization of water clusters with sophisticated electronic structure techniques remains an important and vibrant area of research. The field of computational quantum chemistry has made significant advances since those pioneering studies. Geometry optimizations of the water dimer can now be carried out at the CCSDTQ level, and CCSD(T) energies can be computed with the aug-cc-pVTZ basis for clusters as large as (H 2 O) 17 . Some of these high-level studies are starting to reveal that the electronic structure is harder to describe for some hydrogen bonds than others. For example, discrepancies between MP2 and CCSD(T) energetics tend to increase when there are qualitative differences in the hydrogen-bonding networks of the water clusters being studied. This review highlights the recent and exciting work in this area and provides an overview of popular strategies for generating reliable properties and benchmark quality energetics for water clusters with correlated wavefunction methods. C 2013 John Wiley & Sons, Ltd.

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Section: Strategies For Extending High-accuracy Methods To Larger Clumentioning

confidence: 81%

Wavefunction methods for the accurate characterization of water clusters

Howard

Tschumper

2013

WIREs Comput Mol Sci

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“…MCSCF embeddings for the ground and excited states differ and the cancellation of E 0 X in Eq. (19) does not occur; to compute the excitation energy, one has to perform two separate calculations for the ground and excited states and subtract their energies,…”

Section: Other Low-scaling Methods In Gamess-usmentioning

confidence: 99%

The fragment molecular orbital method: theoretical development, implementation in GAMESS, and applications

Fedorov

2017

WIREs Comput Mol Sci

133

122

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The physical picture of the fragment molecular orbital (FMO) method is described on the basis of a many‐body expansion with terms describing the polarization of isolated fragments, charge transfer (CT), and exchange‐repulsion (EX) between them. Aspects of fragmentation are discussed in detail and FMO development in GAMESS‐US is summarized. Recent progress in method development and applications is reviewed, with a focus on studies of protein–ligand binding, excited states, and spectra of large molecular systems. WIREs Comput Mol Sci 2017, 7:e1322. doi: 10.1002/wcms.1322 This article is categorized under: Structure and Mechanism > Computational Biochemistry and Biophysics Electronic Structure Theory > Ab Initio Electronic Structure Methods

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“…58 Table I summarizes how we categorize various approaches on the basis of the elemental classification scheme suggested above. 59 Further examples of this classification scheme are discussed in the supplementary material, 61 where we discuss the fragment molecular orbital method, 53-55 the kernel energy method, 62-65 the hybrid many-body interaction method, [15][16][17] and various ONIOM-like QM:QM methods, 8,[18][19][20][21][22][23] in addition to methods already mentioned explicitly above.…”

Section: E Unified View Of Existing Fragment Methodsmentioning

confidence: 99%

“…The total system energy can be determined from the subsystem energies by means of a many-body expansion (MBE), 1,13,14 truncated at some finite order. Higherorder terms are sometimes included by performing a full supersystem calculation at a lower level of theory, [15][16][17][18][19][20][21][22][23] which might be a force field. [14][15][16][17] (Hybrid methods of this sort fit within the ONIOM-type formalism mentioned above.)…”

Section: Further Distinguish Between Three Different Types Of Fragmenmentioning

confidence: 99%

A generalized many-body expansion and a unified view of fragment-based methods in electronic structure theory

Richard

Herbert

2012

The Journal of Chemical Physics

214

331

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Fragment-based quantum chemistry methods are a promising route towards massively parallel electronic structure calculations in large systems. Unfortunately, the literature on this topic consists of a bewildering array of different methods, with no clear guiding principles to choose amongst them. Here, we introduce a conceptual framework that unifies many of these ostensibly disparate approaches. The common framework is based upon an approximate supersystem energy formula for a collection of intersecting (i.e., overlapping) fragments. This formula generalizes the traditional many-body expansion to cases where the "bodies" (fragments) share some nuclei in common, and reduces to the traditional many-body expansion for non-overlapping fragments. We illustrate how numerous fragment-based methods fit within this framework. Preliminary applications to molecular and ionic clusters suggest that two-body methods in which dimers are constructed from intersecting fragments may be a route to achieve very high accuracy in fragment-based calculations.

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Analytic gradients for the multicentred integrated QM:QM method for weakly bound clusters: efficient and accurate 2-body:many-body geometry optimizations

Cited by 33 publications

References 27 publications

Wavefunction methods for the accurate characterization of water clusters

Wavefunction methods for the accurate characterization of water clusters

The fragment molecular orbital method: theoretical development, implementation in GAMESS, and applications

A generalized many-body expansion and a unified view of fragment-based methods in electronic structure theory

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