Before revision:  To model the interactions of many molecules at large lengthscales, such as in cellular signal transduction, particle-based reaction-diffusion (RD) simulations are more suitable but come at the price of sacrificing molecular detail.
After revision:  To model the interactions of many molecules at large lengthscales, such as in cellular signal transduction, particle-based reaction-diffusion (RD) simulations are more suitable but lack molecular detail.