Computing Classical Trajectories of H_2O Molecule by Symplectic Algorithm
Huaimin Wang · 2005
Classical movement of H_2O molecule is computed by simplectic algorithm in this paper.On the basis of classical model and H_2O molecule potential function proposed by J.N.Murrell et al,the canonical coordinates and canonical moment as well as Hamilton canonical equations in mass center coordinates have been deduced,classical trajectories and energy of H_2O molecule have been computed.The computed result is compared with the result computed by Runge-Kutta method.The computed results indicate that simplectic scheme can keep energy of H_2O system conservative,which is consistent with theory and experiments,in 10~(-9) second;but energy computed by Runge-Kutta method is changing quickly with time,which is not consistent with theory and experiments.