We used the DV-X alpha cluster method to calculate the electronic state of La4/3-yLi3yTi2O6 (y=0.21). The model cluster used is the formula LiTi8O20 and the density of state (DOS), the bond overlap population (BOP) and the net charge (NC) were calculated. A Li ion in the model cluster was moved from 1b site to another 1b site along the x-axis, and the BOP and the NC calculated were discussed. The potential energy was calculated with the movement of the Li ion along the x-axis. (c) 2005 Elsevier B.V. All rights reserved.