Grain boundary computer simulations

The structures of phases such as the chiral nematic, the blue phases and the twist grain boundary phases are known to result from the presence of chiral interactions between the constituent molecules [3]. It should be possible, therefore, to explore the properties of such phases with computer simulations by introducing chirality into the pair potential and this can be achieved in two quite different ways. In one a point chiral interaction is added to the Gay-Berne potential in essentially the same manner as electrostatic interactions have been included (see Sect. 7). In the other, quite different approach a chiral molecule is created by linking together two or more Gay-Berne particles as in the formation of biaxial molecules (see Sect. 10). Here we shall consider the phases formed by chiral Gay-Berne systems produced using both strategies. 

R.W. Balluffi, T. Kwok, P.D. Bristowe, A. Brokman, P.S. Ho, and S. Yip. Determination of the vacancy mechanism for grain-boundary self-diffusion by computer simulation. Scripta Metall. Mater., 15(8) 951—956, 1981. 

A grain boundary is, formally at least, two surfaces back-to-back. The two crystallites joined by the boundary are rotated with respect to each other. If the axis of rotation is parallel to the interface, the boundary is called a tilt, if perpendicular it is called at twist. Most boundaries are combinations of these extremes. All simulations of grain boundaries have been of highly symmetric structures because of computational limitations. 

Grest GS, Srolovitz DJ, Anderson MP (1985) Computer simulation of grain growth, 4. Anisotropic grain-boundary energies. Acta Metall 33 509-520... 

FtGURE 9.15 Classification of computer simulation models for soap froth and grain boundary evolution. (From Ref. 13.)... 

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