“…For the numerical study of Hamiltonian PDEs, the multi-symplectic structure is investigated and then a lot of reliable numerical methods (e.g. [7,8,9,10,11,12,13,14]) preserving the multi-symplectic structure, for instance, muti-symplectic RK/PRK methods, collocation methods, splitting methods, spectral methods, etc., have been developed. Especially, we refer to [10,15,16,17] and references therein for the multi-symplectic methods of Hamiltonian wave equations.…”