The LAMMPS package complied with the DeePMD-kit package was employed to do the simulations. Hybrid DeePMD and grand canonical Monte Carlo (GCMC) method was used to simulate the lithiation processes of c-Si/a-Si and delithiation processes of c-Li3.75Si/a-Li4.5Si. The isothermal-isobaric (NPT) ensemble was adopted during the simulations. For GCMC, we performed one attempt of random Li insertion and two attempts of random Li translation every 100 MD timesteps. The total simulation time of a complete hybrid DeePMD + GCMC process was 5 and 8 ns for lithiation and delithiation, respectively. The time interval of a single MD step was 1 fs. After the hybrid simulations, we picked the lowest energy configurations of each composition. The configurations were then simulated by DeePMD under the NPT ensemble for another 10 ns, and the structures were finally relaxed, on which further analysis of formation energies, voltage curves and atomic structures was investigated. For the lithiation of a-Si, the detailed scheme is shown in Figure . We can see that good agreement for energies and forces is achieved over a broad range of Li-Si compositions and structures, including crystalline and amorphous Li, Si, and LixSi. The root mean square error (RMSE) of energy of c-LixSi and a-LixSi is 0.015 and 0.008 eV/atom, respectively. The force RMSE of c-LixSi and a-LixSi is 0.119 and 0.170 eV/Å, respectively. , where the error is in the range of 0.07%~0.45%. The predicted voltage curve of crystalline phases by the DP model is also compared to that of DFT (see Figure ). These agreements guarantee reliable simulation results of the lithiation/delitheation processes in the Si anode.