To obtain a suitable set of coordinates to describe the intramolecular proton transfer, we initially optimized the salicylaldimine transition state (TS) for the transfer step. We then calculated the Hessian at the TS and used this to obtain a set of 42 normal mode coordinates. Following previous work on this system, we use only a minimal number of these modes in order to describe the dynamics at the fully coupled MCTDH level of theory.