Quantum-Mechanical/Molecular-Mechanical (QM/MM) Simulations for Understanding Enzyme Dynamics

The interpretation problems of quantum theory are considered. In the formalism of quantum theory the possible states of a system are described by a state vector. The state vector, which will be represented as |Ïˆ> in Dirac notation, is the most general form of the quantum mechanical description. The central problem of the interpretation of quantum theory is to explain the physical significance of the |Ïˆ>. In this paper we have shown that one of the best way to make of interpretation of wave function is to take the wave function as an operator.

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Optical and Electrical Properties of Organic Conducting Polymers

JOURNAL OF ADVANCES IN CHEMISTRY ◽

10.24297/jac.v8i1.7103 ◽

2014 ◽

Vol 8 (1) ◽

pp. 1457-1463

Author(s):

Salah Abdulla Hasoon

Keyword(s):

Electrical Properties ◽

Conjugated Polymer ◽

Polymeric Materials ◽

Quantum Mechanical ◽

Optical And Electrical Properties ◽

Electrically Conducting ◽

Temperature Ranges ◽

Lithium Tetrafluoroborate ◽

Absorbance Peak ◽

Polymerization Method

Novel electrically conducting polymeric materials are prepared in this work. Polythiophene (PT) and poly (3-Methelthiophene) (P3MT) films were prepared by electro-polymerization method using cyclic voltammetry in acetonitrile as a solvent and lithium tetrafluoroborate as the electrolyte on a gold electrode. Electrical properties of P3MT have been examined in different environments using UV-Vis absorption spectroscopy and quantum mechanical ab initio calculations, The observed absorption peaks at 314 and 415 nm, were attributed to the n-π* and π-π* transitions, respectively in the conjugated polymer chain, in contrast, the observed absorbance peak at 649 nm, is responsible for electric conduction. The temperature dependence of the conductivity can be fitted to the Arrhenius and the VTF equations in different temperature ranges.

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Brief History of Quantum Mechanical Methods in Atomic Theory and Hidden Symmetries

Old and New Concepts of Physics ◽

10.2478/v10005-007-0037-4 ◽

2008 ◽

Vol 5 (2) ◽

pp. 311-319

Author(s):

Yu. P. Rybakov

Keyword(s):

Quantum Mechanical ◽

Hidden Symmetries ◽

Atomic Theory ◽

Mechanical Methods ◽

History Of

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Bonded Force Constant Derivation of Lysine-Arginine Cross-linked Advanced Glycation End-Products

10.26434/chemrxiv.5891602.v2 ◽

2018 ◽

Author(s):

Anthony Nash ◽

Nora H de Leeuw ◽

Helen L Birch

Keyword(s):

Molecular Dynamics ◽

Force Constant ◽

Computational Study ◽

Force Constants ◽

Quantum Mechanical ◽

Advanced Glycation ◽

Partial Charges ◽

Cross Links ◽

Complete Set ◽

Dynamics Simulations

<div> <div> <div> <p>The computational study of advanced glycation end-product cross- links remains largely unexplored given the limited availability of bonded force constants and equilibrium values for molecular dynamics force fields. In this article, we present the bonded force constants, atomic partial charges and equilibrium values of the arginine-lysine cross-links DOGDIC, GODIC and MODIC. The Hessian was derived from a series of <i>ab initio</i> quantum mechanical electronic structure calculations and from which a complete set of force constant and equilibrium values were generated using our publicly available software, ForceGen. Short <i>in vacuo</i> molecular dynamics simulations were performed to validate their implementation against quantum mechanical frequency calculations. </p> </div> </div> </div>

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Quantum Mechanical Interpretation of the Ultra-Low Energy Methyl-Rotation Dynamics in Porous Metal-Organic Frameworks Probed by Low-Frequency Vibrational Spectroscopy and ab initio Simulations

10.26434/chemrxiv.5995078.v1 ◽

2018 ◽

Author(s):

Qi Li ◽

Adam J. Zaczek ◽

Timothy M. Korter ◽

J. Axel Zeitler ◽

Michael T. Ruggiero

Keyword(s):

Ab Initio ◽

Metal Organic Frameworks ◽

Low Frequency ◽

Rotor Dynamics ◽

Quantum Mechanical ◽

Valuable Insight ◽

Void Space ◽

Ab Initio Simulations ◽

Metal Organic ◽

Insight Into

<div>Understanding the nature of the interatomic interactions present within the pores of metal-organic frameworks</div><div>is critical in order to design and utilize advanced materials</div><div>with desirable applications. In ZIF-8 and its cobalt analogue</div><div>ZIF-67, the imidazolate methyl-groups, which point directly</div><div>into the void space, have been shown to freely rotate - even</div><div>down to cryogenic temperatures. Using a combination of ex-</div><div>perimental terahertz time-domain spectroscopy, low-frequency</div><div>Raman spectroscopy, and state-of-the-art ab initio simulations,</div><div>the methyl-rotor dynamics in ZIF-8 and ZIF-67 are fully charac-</div><div>terized within the context of a quantum-mechanical hindered-</div><div>rotor model. The results lend insight into the fundamental</div><div>origins of the experimentally observed methyl-rotor dynamics,</div><div>and provide valuable insight into the nature of the weak inter-</div><div>actions present within this important class of materials.</div>

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