我的方向是第一性原理计算。该系统是钾离子电池的正极材料K0.5MnO2，旨在通过原子掺杂计算K离子迁移能垒,I used CI-NEB to calculate the transition state, but it never converges. Even if the accuracy is very low, it still doesn't work. Each time, it takes more than ten days, and the energy keeps changing. Moreover, the energy at the intermediate insertion points is lower than that at the initial and final states, making it impossible to proceed with the next calculation.

My initial and final state structure involves deleting one K ion and then I'd like to consult the experts and offer some suggestionsmigrating the nearest adjacent K ion to the vacancy. The modeling should be fine, right? (Both the initial and final states have been structurally optimized and ISIF=2)