Very commonly, molecules don't evolve simply under quantum mechanics-the evolution is interrupted by exchange or reactions. The study of this kind of coherent evolution in dynamic systems is at the forefront of many disciplines, but has been prominent in magnetic resonance for more than 50 years. However, the arguments that led to the theoretical formalism were motivated under incorrect assumptions. The Warren lab has recently reported on a complete re-interrogation of this problem, and has presented a corrected theory that is converged to infinite-order. This permits highly efficient simulations of complex quantum systems, and has provided insight into the development of new experimental methods. The results were published in Science Advances, with Jake Lindale as first author. Read more about their findings here.