“…Different parameter regimes could be considered for the Dirac equation (1.7) (or (1.17 of bound states and/or standing wave solutions, we refer to [26,27,32,40,41,52] and references therein. In this parameter regime, for the numerical part, many efficient and accurate numerical methods have been proposed and analyzed [3], such as the finite difference time domain (FDTD) methods [4,50], time-splitting Fourier pseudospectral (TSFP) method [9,42,20], exponential wave integrator Fourier pseudospectral (EWI-FP) method [9], the Gaussian beam method [62], etc.…”