Density map of collision between domain wall and anti-domain wall. It is seen that the profiles of parts between kink and anti-kink in each component both vary greatly after the collision, the kinks’ profiles flipped over. The parameters are λ 1 = − 0.5 , λ 2 = 0.5 , k 1 = k 2 = 1 , c 1 = c 2 = 2 , α 1 = α 2 = 0 .