Bonding states near to the body-centered cubic edge dislocation core were studied, on the basis of the Peierls-Nabarro dislocation model, by using the discrete variational Xα method. The slip systems were {112}<111> and {110}<111>. Molecular orbital calculations for cluster models with 32 atoms, belonging to the perfect crystal, and Peierls edge dislocation core models were used to estimate bond orders and net charge distributions among atoms in the cluster models. In the case of the {112}<111> slip system, the total bond order between the nearest-neighbour atoms of the dislocation model was found to be larger than that of the perfect crystal model. However, the total bond order of the second-neighbour atoms in the dislocation model was a little smaller than that in the perfect crystal model. It was also found that there was an asymmetry, in the bond order, between the left side and the right side of the (110) plane which contained the core atoms of the dislocation. The net charge in the dislocation model was larger than that in the perfect crystal model. Essentially the same results were found for the {110}<111> slip system.

An Evaluation of Bonding States of BCC(Fe) Edge Dislocation Core by DV-Xα Cluster Method. T.Fukuda, M.Hida, A.Sakakibara, Y.Takemoto: Journal of the Japan Institute of Metals, 2001, 65[9], 852-7