Accession Number : ADA309359

Title :   Molecular Spectra and Dynamics at Interfaces.

Descriptive Note : Final technical rept. 1 Dec 94-30 Nov 95,

Corporate Author : FLORIDA UNIV GAINESVILLE QUANTUM THEORY PROJECT

Personal Author(s) : Ohrn, N. Y. ; Micha, David A.

PDF Url : ADA309359

Report Date : 15 MAY 1996

Pagination or Media Count : 4

Abstract : Treatment of the simultaneous dynamics of electrons and nuclei with full account of electron nuclear coupling has been applied to polymeric chains. Only the highest frequency longitudinal and transverse vibrational modes couples strongly to the electrons. The quantum dynamics of electron transfer at metal surfaces and of the dissociation of diatomic adsorbates have been investigated to construct models of bonding and dynamics at surfaces, and to calculate rates of ion - neutralization, and photodesorption times. Electronic charge transfer, leading to ion neutralization, was studied for the system Na(+) + W(110). A method has been developed to treat the coupling of the very different time scales present in molecular dynamics for nuclear (slow) and electronic (fast) motions; it has been based on density operators in Liouville space. The photodissociation of CO adsorbed on the Ni(001) surface by visible and UV light has been described using wavepacket dynamics for two coupled potential energy surfaces, including the vibrational degree of freedom of CO. The treatment incorporates dissipation and force fluctuations at the metal surface, within the diabatic electronic representation. Calculations show that dissipation by electron-hole excitation is a dominant mechanism.

Descriptors :   *MOLECULAR SPECTROSCOPY, *DYNAMICS, *INTERFACES, *ELECTRONS, *NUCLEI, ELECTRONICS, IONS, METALS, DENSITY, VIBRATION, COMPUTATIONS, ULTRAVIOLET RADIATION, MODELS, PHOTOCHEMICAL REACTIONS, PHOTODISSOCIATION, POLYMERS, EXCITATION, QUANTUM THEORY, NEUTRALIZATION, LIGHT, DISSIPATION, SODIUM, HOLES(ELECTRON DEFICIENCIES), VARIATIONS, SURFACES, CHAINS, CHARGE TRANSFER, BONDING, DIATOMIC MOLECULES, NICKEL, SYNCHRONISM, ELECTRON TRANSFER, DISSOCIATION, DESORPTION, MOLECULAR PROPERTIES, TUNGSTEN, ADSORBATES.

Subject Categories : Physical Chemistry
      Polymer Chemistry
      Atomic and Molecular Physics and Spectroscopy
      Quantum Theory and Relativity

Distribution Statement : APPROVED FOR PUBLIC RELEASE