Results 221 to 230 of about 40,239 (260)
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Ureases: Quantum Chemical Calculations on Cluster Models
Journal of the American Chemical Society, 2003Herein, we present results from a computational study of dinickel complexes that are relevant to the catalytic hydrolysis of urea exerted by the urease enzymes. The B3LYP density functional is used to characterize the equilibrium geometry, electronic and magnetic properties, and energies for a series of realistic complexes modeling the active site of ...
Dimas, Suárez +2 more
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Quantum Chemical Modeling and Preparation of a Biomimetic Photochemical Switch
Angewandte Chemie, 2006Designing and testing biomimetic switches: Multireference perturbation theory is used to model a light‐driven molecular switch featuring the same photoisomerization mechanism as the chromophore of the visual pigment rhodopsin (see picture; QM/MM: quantum mechanics/molecular mechanics).
Lumento, F. +10 more
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Quantum-Chemical Modeling of Ag/CeO2 Nanoscale Catalysts
Russian Journal of Physical Chemistry A, 2023The authors summarize results from calculations using the density functional theory for atoms and small silver clusters on surfaces of nanostructured cerium(IV) oxide, along with the adsorption and transformations of O2 and CO molecules on these systems.
E. A. Shor, A. M. Shor, V. A. Nasluzov
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Quantum Chemical Models (Nobel Lecture)
Angewandte Chemie International Edition, 1999The solving of chemical problems to which the answer is unknown or in dispute is the important objective of each theoretical model. How far quantum chemistry has come in this respect is described here for the ab initio concept, which is known to just about every chemist under the name GAUSSIAN.
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Quantum Chemical and QM/MM Models in Biochemistry
2019Quantum chemical (QC) calculations provide a basis for deriving a microscopic understanding of enzymes and photobiological systems. Here we describe how QC models can be used to explore the electronic structure, dynamics, and energetics of biomolecules.
Patricia, Saura +3 more
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Quantum chemical models for electrified interfaces
Chemical Physics Letters, 1994Abstract Quantum chemical models for a charged interface are discussed. A new approach based on the renormalization of the density matrix is proposed in order to describe a continual surface charge distribution. Ab initio quantum chemical calculations were carried out for a small mercury cluster.
Renat R. Nazmutdinov +2 more
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1997
Over centuries of development of science, it gradually became clear that our theories are unable to reflect the “physical reality” in all its complexity but can only supply models which describe certain aspects of some phenomena. The Newtonian mechanics, the Maxwellian electrodynamics, thermodynamics, statistical physics, the special and the general ...
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Over centuries of development of science, it gradually became clear that our theories are unable to reflect the “physical reality” in all its complexity but can only supply models which describe certain aspects of some phenomena. The Newtonian mechanics, the Maxwellian electrodynamics, thermodynamics, statistical physics, the special and the general ...
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Quantum-chemical modeling of smectite clays
Inorganic Chemistry, 1982A self-consistent charge extended Hueckel program is used in modeling isomorphic substitution of Al(3+) by Na(+), K(+), Mg(2+), Fe(2+), and Fe(3+) in the octahedral layer of a dioctahedral smectite clay, such as montmorillonite. Upon comparison of the energies involved in the isomorphic substitution, it is found that the order for successful ...
S. Aronowitz +3 more
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Quantum Chemical Modeling of the Dehalogenation Reaction of Haloalcohol Dehalogenase
Journal of Chemical Theory and Computation, 2008The dehalogenation reaction of haloalcohol dehalogenase HheC from Agrobacterium radiobacter AD1 was investigated theoretically using hybrid density functional theory methods. HheC catalyzes the enantioselective conversion of halohydrins into their corresponding epoxides. The reaction is proposed to be mediated by a catalytic Ser132-Tyr145-Arg149 triad,
Kathrin H, Hopmann, Fahmi, Himo
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Modeling Reductive Dehalogenation with Quantum Chemically Derived Descriptors
SAR and QSAR in Environmental Research, 1995Existing models for the reductive dehalogenation reaction under environmentally relevant conditions use Hammett and Taft coefficients as descriptors. Drawbacks of these descriptors are the limited possibilities for interpretation in terms of reaction mechanisms, and the limited availability of these descriptors for more "exotic' substituents. Therefore,
E, Rorije +3 more
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