9412887 This proposal attempts to link atomistic and continuum properties of materials. The PIs focus here mainly on interfaces and surfaces. A local definition of the elastic properties is developed which allows a good description of localized long wavelength vibrational modes at grain boundaries in single component metals and alloys, and at bimaterial interfaces. The PIs plan to extend their work to more complex systems described by angular dependent (covalent) forces. This work is anticipated to be of use also for studying dislocation motion and crack propagation. %%% This proposal concerns an attempt to tie together the large scale and small scale way of describing materials behavior. It concerns, in particular, the local vibrational properties at internal surfaces; that is grain boundaries and the plane which separates two dissimilar materials in contact. The PIs previous work concerned systems whose atoms interact via very simple force laws. The new work should become more useful as it is applied to more complicated systems such as semiconductors and transition metals (like iron). This work is extremely useful since it tries to meld together two alternative ways of describing the properties of materials.
