Molecular graphics and the classical adiabatic and nonadiabatic dynamics of small polyatomic reactions

 

 

 

L. J. Dunne and N. L. Bourner

 

South Bank Polytechnic, London, SE1 OAA, UK

 

 

 

Summary

 

This paper was written in the early stages of the development of molecular dynamics. Attention was given to the dynamics of the reaction. Classical trajectory methods are better than quantal methods in the sense that the trajectories of atoms are interpretable on successive time intervals. Classical trajectory computer programs compute the phase space variables. These variables are time, t, and the set of atomic coordinates (Q_i) and momenta (P_i) and the functions of these phase space variables. Nonadiabatic program compute Ψ or the density matrix ρ as a function of time.

 

The programs were written in FORTRAN 77, and PICASO drawing system was used to visualize the resulting trajectories. The atoms were considered as spheres. The atomic path as a function of time was computed by

 

 

Photodissociation reaction of water at 10eV was studied. Hodgson et al. and other researchers had already published the intersection of B state surface and X state surface. In this study, the published results were visualized graphically. It was found that the computer graphics system is very helpful to study the classical trajectories of molecular reaction dynamics. It was the work at the initial stages of the development of molecular dynamics and can help to understand the importance of visualization of trajectories of atoms and molecules.

 

 

 

Reviewer: Aamir Alaud Din

 

Email: aamiralauddin@gist.ac.kr