Theoretical Studies Of Polyatom Reaction Dynamics And Biomolecular

Quantum dynamics study of polyatomic reaction and accurate quantum mechanical calculation for biological molecules such as proteins are very important topics in computational chemistry and biology.This dissertation is organized as follows: Part I: Semirigid vibrating rotor target (SVRT) model is applied to study the reaction of atom-polyatoms using time-dependent wave packet method. Part II: Molecular fractionation with conjugate caps (MFCC) approach is applied to calculate electron density and electrostatic potential of proteins.Over the past twenty years, with the development of quantum scatting theory and the enhancement of computational capacity, it has been possible to take full quantum calculation on reactions with no more than four atoms. But in chemical and biological fields, reactions always deal with more than four atoms. So, to take accurate full quantum calculations on such reactions, some models and dimension-reduced computational methods have been development to reduce the calculational difficulty such as adiabatic approach, fixed geometry approximations and mixed quantum-classical dynamics methods.In the SVRT model, the reacting molecule is treated as a semirigid vibrating rotor which can be considered as a three-dimensional generalization of the diatomic molecule. This model provides a realistic framework to treat reaction dynamics of polyatomic systems. Using the SVRT model, it becomes computationally practical to carry out quantitatively accurate quantum dynamics calculation for a variety of dynamics problems in which the reacting molecule is a polyatomic or complex molecule.Since the SVRT model can deal with the special locomotion, it correctly includes...