Application Of Precise Time Step Integration Method In Molecular Dynamics

Molecular Dynamics(MD)is a very important computer simulation experiment method. And had been used widely in many fields.Precise Time Step Integration Method(PTSIM) has outstanding advantages with accuracy and stability in solving homogeneous equation of dynamic equation.This paper uses the primary theory of PTSIM in the research of molecular dynamics for the first time.Aiming at this issue as well as the problems of various special circumstances, given the corresponding new precise integration formats.Compared to the traditional integration algorithm of MD,the advantages of precision,efficiency and parallelism calculated by PTSIM are elaborated on.The main work of this paper can be summarized as follows:(1) Various kinds of nonlinear precise integration method in recent years are summarized through and studyed thoroughly.They are compared to each other through an example analysis,these methods are applied to prepare for MD.(2) The application of precise integration method in molecular dynamics was researched. According to conservative system,a new kind of precise integration method was given.It is to avoid the inverse matrix and nonlinear term for higher-order derivatives,also need not add dimension and format is simple,can reflect the molecular dynamics and the time step closer relations between the compliance.This way,can carry out characteristics of the precise integration processing matrix.For a dissipative system,gives a precise integration method that is to derivative nonlinear term directly.This method was "abandoned in approximate derivative. Precision is guaranteed.It is no relationship between computational complexity and damping matrix of complexity.The more complex damping matrix is,the higher efficiency.In an external force system,gives a precise integration format that nonlinear term has direct integration by using Cotes formula.When the external force is very complex,this format can undertake parallel computing time which traditional algorithm can't.Finally,through the theoretical analysis and numerical example comparison,illustrates that the precise integration method applied in molecular dynamics is feasible and has advantages.And the more complex the external force is,the advantages are more obvious.