We also considered a technique for parallel computing, wherein the entire algorithm was divided into two modules: SMC and the aforementioned validation calculation of products and properties using the forward models. The SMC module sequentially feeds the reactants sampled at each step into the module of the forward model. The forward-prediction module calculates the synthetic products and properties of the received reactants and adds the calculated products to the pool of candidate reactants in the SMC module. These two units carry out the computation of the reactant sets flowing from the different steps of SMC. The two modules perform their tasks simultaneously once the data exchange is complete, synchronizing the timing of the data exchange, as schematically described in Figure . The SMC module proceeds with its calculation as t = 0, 1, . . . without any suspension (top row). In contrast, the forward-prediction module is subject to an idle state. Once the calculation of one step of the SMC is completed, the set of reactants produced there is handed over to the module for the forward calculation in an idle state. The forward-prediction module then calculates the predicted products using Molecular Transformer, which are sent back to the SMC module. Once the data transfer is completed, the forward-prediction module returns to the idle state and waits to receive the next reactant set. In the example shown in Figure , we assume that the SMC module is approximately 2.5 times faster than the forward-prediction module. In this case, three forward-prediction modules are allocated to different processing units in order to reduce the idling time as much as possible.