Physics Commons^™

Restricted Dislocation Motion In Crystals Of Colloidal Dimer Particles, Sharon J. Gerbode, Stephanie H. Lee, Chekesha M. Liddell, Itai Cohen

All HMC Faculty Publications and Research

Received 2 April 2008; published 1 August 2008; corrected 1 October 2008

At high area fractions, monolayers of colloidal dimer particles form a degenerate crystal (DC) structure in which the particle lobes occupy triangular lattice sites while the particles are oriented randomly along any of the three lattice directions. We report that dislocation glide in DCs is blocked by certain particle orientations. The mean number of lattice constants between such obstacles is Z̅ _exp=4.6±0.2 in experimentally observed DC grains and Z̅ _sim=6.18±0.01 in simulated monocrystalline DCs. Dislocation propagation beyond these obstacles is observed to proceed through dislocation reactions. …

A Semiclassical Model For Orientation Effects In Electron Transfer Reactions, Robert J. Cave, Stephen J. Klippenstein, R.A. Marcus

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An approximate solution to the single‐particle Schrödinger equation with an oblate spheroidal potential well of finite depth is presented. The electronic matrix element H_BA for thermal electron transfer is calculated using these wave functions, and is compared with values of H_BA obtained using the exact solution of the same Schrödinger equation. The present method yields accurate results for H_BA, within the oblate spheroidal potential well model, and is useful for examining the orientational effects of the two centers on the rate of electron transfer.

A Model For Orientation Effects In Electron‐Transfer Reactions, Paul Siders, Robert J. Cave, R.A. Marcus

All HMC Faculty Publications and Research

A method for solving the single‐particle Schrödinger equation with an oblate spheroidal potential of finite depth is presented. The wave functions are then used to calculate the matrix element T_BA which appears in theories of nonadiabatic electron transfer. The results illustrate the effects of mutual orientation and separation of the two centers on T_BA. Trends in these results are discussed in terms of geometrical and nodal structure effects. Analytical expressions related to T_BA for states of spherical wells are presented and used to analyze the nodal structure effects for T_BA for the spheroidal wells.