Download or read book Large Amplitude Motion in Molecules I written by Springer and published by . This book was released on 2014-01-15 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large Amplitude Motion in Molecules I written by Friedrich L. Boschke and published by Springer. This book was released on 2014-04-17 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large Amplitude Motion in Molecules II written by Springer and published by . This book was released on 2014-01-15 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large Amplitude Motion in Molecules written by and published by . This book was released on 1979 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large Amplitude Motion in Molecules II written by Kendall N. Houk and published by Springer. This book was released on 2013-11-20 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large Amplitude Motion in Molecules written by Lawrence Steven Bernstein and published by . This book was released on 1974 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large Amplitude Motion in Molecules written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wide amplitude Motion in Molecules written by Florence Jean Lin and published by . This book was released on 1984 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spectroscopy and Dynamics of Small Molecules with Large Amplitude Motion written by Mahesh B. Dawadi and published by . This book was released on 2014 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Dynamics of Large Amplitude Motion in Energized Molecules written by and published by . This book was released on 2016 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemical reactions involve large-amplitude nuclear motion along the reaction coordinate that serves to distinguish reactants from products. Some reactions, such as roaming reactions and reactions proceeding through a loose transition state, involve more than one large-amplitude degree of freedom. Because of the limitation of exact quantum nuclear dynamics to small systems, one must, in general, define the active degrees of freedom and separate them in some way from the other degrees of freedom. In this project, we use large-amplitude motion in bound model systems to investigate the coupling of large-amplitude degrees of freedom to other nuclear degrees of freedom. This approach allows us to use the precision and power of high-resolution molecular spectroscopy to probe the specific coupling mechanisms involved, and to apply the associated theoretical tools. In addition to slit-jet spectra at the University of Akron, the current project period has involved collaboration with Michel Herman and Nathalie Vaeck of the Université Libre de Bruxelles, and with Brant Billinghurst at the Canadian Light Source (CLS).
Download or read book Dynamics of Coupled Large Amplitude Motions from Small Non rigid Molecules to Conjugated Polymers written by Ram S. Bhatta and published by . This book was released on 2012 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: Large amplitude motions (LAMs) such as torsional and inversion motions are present in a variety of molecular systems ranging from small non-rigid molecules to polymers and play a crucial role in nuclear dynamics. This dissertation presents theoretical studies of LAM dynamics present in small molecules and polymers based on the quantum and classical approaches. On the small molecular side, high-level quantum calculations are performed to calculate high quality torsion-inversion potential energy surfaces for CH3XH2 (X=C, N, O). The torsion-inversion coupling is found to be in the range 280 [less than or equal to] V1,3 [less than or equal to] 450 cm−1. Torsion-inversion Hamiltonian is constructed and torsioninversion energy levels as well as spectroscopic parameters are calculated for these molecular species. The frequency calculation at each stationary point of the surface is performed as well as the calculation of the two-dimensional torsion-inversion force constant surface. On the polymer side, nuclear dynamics are studied performing classical molecular dynamics (MD) simulations. The force field required for the MD simulations are derived from ab initio calculations. Both static and dynamical properties of poly(3-hexylthiophene) (P3HT), a promising solar cell material, are calculated. These properties include structural parameters, density, surface tension, glass transition temperature and melting temperature.
Download or read book Quantum mechanical study of large amplitude motion in small polyatomic molecules written by Joseph Allen Bentley and published by . This book was released on 1991 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Improved Election Gas Drude Model Theory written by Marvin Waldman and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Timescales of Large Amplitude Motion written by and published by . This book was released on 2014 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis comprises two projects that investigate vibrational energy relaxation (VER), and symmetric proton tunneling. In the first project, we investigate the pathways of VER in the molecule iso-chloroiodomethane embedded in a matrix of argon at 12K, motivated by the experimental studies of Crim and coworkers. We study this relaxation theoretically using molecular dynamics by considering two and three dimensional models. Multiple decay rate constants of the same order of magnitude as the experiment are observed. These decay rate constants are interpreted within the context of the Landau-Teller theory. Sensitivity of the decay rate constants on the bath and system parameters shed more light into the mechanism of VER. The second project focuses on proton tunneling, which plays a central role in many biological reactions. We investigate a three dimensional model Hamiltonian coupled to a harmonic bath that describes concerted proton transfer in formic acid dimer. The three modes provide a paradigm for the symmetric and anti-symmetric coupled tunneling pathways. The effects of temperature and coupling to the bath on the rates are presented. We compare three methods that have been shown previously to provide good results for the tunneling dynamics -- surface hopping, ring polymer molecular dynamics, and the Makri-Miller method. We find that surface hopping and ring polymer molecular dynamics do not describe some aspects of the dynamics in the deep tunneling regime due to neglect of the coherence effects. Certain modifications in the surface hopping algorithm are suggested to partially include these coherences. The Makri-Miller method predicts the correct trends for the tunneling splittings, which govern the dynamics. In addition, we also develop a new method to compute tunneling splittings for highly excited states. This method is based on making an adiabatic approximation to the Herring estimate, and is in excellent agreement with the exact results.
Download or read book Vibrational rotational Spectroscopy And Molecular Dynamics written by Dusan Papousek and published by World Scientific. This book was released on 1997-10-31 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book reviews the results of vibration-rotational spectroscopy of molecules obtained recently by combining modern computational methods of quantum chemistry with the new techniques of high-resolution rotational and vibration-rotational spectroscopy. It shows for example that the tunneling vibration-rotational spectroscopy of the van der Waals complexes provides a new look at intermolecular forces while the high precision and sensitivity of the submillimeter-wave and Fourier transform microwave spectroscopy make it possible to study complex rotational spectra of molecules in excited vibrational states. New results of high level ab initio quantum chemical computations of vibrational and rotational energy levels and dipole moment functions of unusual molecules will be discussed together with the recent discovery of clustering of energy levels in asymmetric tops. Group theoretical analysis of floppy molecules, especially the tunneling effects in nonrigid molecules, will also be discussed.
Download or read book Theoretical and Computational Chemistry written by Iwona Gulaczyk and published by Walter de Gruyter GmbH & Co KG. This book was released on 2021-06-08 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explores the applications of computational chemistry ranging from the pharmaceutical industry and molecular structure determination to spectroscopy and astrophysics. The authors detail how calculations can be used to solve a wide range of practical challenges encountered in research and industry.
Download or read book Large Amplitude Motion in Polymer Crystals and Mesophases written by and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
