In this letter we present a new approach to find analytical twiston models. The effective twofield model was constructed by a non-trivial combination of two one field systems. In such an approach we successfully build analytical models which are satisfied by a combination of two defectlike solutions, where one is responsible to twist the molecular chain by 180 0 , while the other implies in a longitudinal movement. Such a longitudinal movement can be fitted to have the size of the distance between adjacent molecular groups. The procedure works nicely and can be used to describe the dynamics of several other molecular chains.