Herein, we propose a novel approach for translating the energy-based square scheme for PCET into real Cartesian space and demonstrate it using three model systems based on phenol, indol, and toluene. These model systems were chosen because they are prototypical examples of PCET. Our starting point for this endeavour was the realisation that the horizontal and vertical axes of the square scheme can never be fully enforced in quantum chemical calculations: the proton and electron motions cannot be completely disentangled if donor and acceptor are described in the same calculation. Separating donor and acceptor into different calculations will neglect their interaction and hence carry inaccuracies. This raises the question of how to define meaningful paths within the (3N -6) dimensional space that encompasses all degrees of freedom relevant to PCET. We make use of the fact that the Marcus-Hush model is expected to describe the ET part of the PCET process, and define the proton movement via a scan between its donor and acceptor positions. These two processes can be used to map out the relevant spatial portion of the square scheme in a straightforward manner. Based on analysis of the PES spanned by the proton and electron motions we propose quantitative definitions for the degrees of coupling and concertedness of the PCET process.