The application provides a method for accurately calculating
mean square displacement (MSD) of
molecular dynamics simulation based on multi-
phase state identification, which accurately classifies target molecules in the
system into four states: near
impurity target molecules, target molecules in hydrates, target molecules in clusters and target molecules in
liquid phase. The classification process adopts a multi-stage screening strategy to ensure the independence of each type of molecule. Traditional MSD calculation only requires molecules to be in the target
phase state at the start and end frames, but the intermediate frame may undergo
phase transition, such as entering the
hydrate from the
liquid phase, resulting in a deviation of the calculation result from the intrinsic
diffusion behavior. The application tracks the occurrence state of the molecule during the entire
simulation process, accurately finds the state that needs to be calculated, and ensures that MSD only reflects the continuous
diffusion process of the molecule in the pure
liquid phase through a state persistence
verification mechanism, excluding the interference of
phase transition, and performing targeted MSD calculation.