The quantum chemistry community has developed analytic forces for approximate electronic
excited states to enable walking on excited state potential energy surfaces (PES). One can
thereby computationally characterize excited state minima and saddle points. Always implicit
in using this machinery is the fact that an excited state PES only exists within the realm of the
Born-Oppenheimer approximation, where the nuclear and electronic degrees of freedom
separate. This work demonstrates through ab initio calculations and simple nonadiabatic …