is the CMES, an effective potential energy surface obtained from constrained energy minimization. This set of equations of motion highly resembles the classical Newton's equation, but instead of the conventional PES, here the V CMES (⟨x⟩) is used, which includes NQEs of the quantum nuclei. In practical molecular simulations, the CNEO methods, especially CNEO-DFT, can be used to obtained V CMES (⟨x⟩) and the CNEO gradients can be used to obtain the force. As such, CNEO-MD can be performed essentially in the same way as the widely used conventional AIMD simulations by replacing the on-the-fly DFT calculations with CNEO-DFT calculations. This slight change leads to a minor increase in computational cost but makes it possible to incorporate NQEs in AIMD simulations.