We present here an analytical thermal vibration correlation function formalism to calculate the nonradiative decay rate constant (k(nr)) considering excitonic coupling effect (ECE) for molecular aggregates based on split-operator approximation. Combining with first-principles calculations, we found that k(nr) is enhanced by ECE for both H- and J-aggregates. In addition, ECE is found to be minor for the AIEgens (aggregation-induced emission luminogens). (C) 2017 Elsevier B.V. All rights reserved.