Equilibrium Positions of Potassium Cation in K3C60 Crystal
K3C60晶体中钾离子的平衡位置

By analyzing the potefitial of an octahedral alboi cation, the varying of the potentialof alkali cation, whose position is in three different directions of 111], 110] and 100] was calculated.The results show that off-center sites in K3C60 crystal actually ealst in these three directions. The deviations from the center are different to be 0.98 , 0.78 , 0.56 respectively in 111], 110] and 100] directions. The potential at off-center site in 111] direction is the lowest, -508.59meV. The existence of officenter sites owes to the short range interaction of alkali, especially the interaction between alkali and C60 anions. The most important is that the site corresponding to the lowest potential point is not at the symmetric center. The reason of the different deviations in these three directions is the different densities of C60 anion in the corresponding crystal planes.