Reaction activation energies (E a ) and heats of reaction (∆H r ) are essential to understanding of reactivity in applications ranging from biofuel utilization, drug design, and materials stability. Collecting this information from experiments is costly, making it highly desirable to develop predictive methods that can be used prior to synthesis to expedite hypothesis formation and optimization. Over the past several decades, quantum chemistry has delivered many algorithms for localizing transition states (TSs) and characterizing activation energies; however, finding transition states remains relatively expensive for on-the-fly and high-throughput applications. It would be a qualitative advance if reaction properties like activation energy could be directly calculated without first localizing a transition state.