By adopting the variable density method,the topological optimization model that took the total flexibility of structure as the objective function and the volume of structure as the constraint was established.

Aiming at improving the limitation of adjustment and interaction by using the traditional geometric modeling methods,this paper addressed the physically-based method and FDM(force density method) for surface modeling.

Ten density functional theory (DFT) methods were compared for calculating the car- bon-hydrogen bond dissociation energies of hydrocarbons.

The acetyl grouptransfer reaction between arylamine N-acetyltransferases andits substrate,paminobenzoicacid(PABA) wasinvestigated by Density Functional Theory B3LYP with6-31 +g(d,p)basis.

The asymmetric reactions of dichloromethane and diiodomethane with (3Z,2S) pentan-3-enyl-2-ol catalyzed by zinc are studied by means of the density functional theory.

LaCn and La2Cn ( n = -1, 0, +1 ) clusters have been studied using density functional method.

LaC 3 n(n =-1,0,+1) clusters have been studied using density functional method.

The possible geometrical and electronic structures of Pdn(n=2-6) clusters were optimized by Gaussian 98 code with the LANL2DZ basis set and density functional method under the approximation of relativistic effective core potential(RECP).

The interaction mechanism between uracil and its molecularly imprinted membrane has been investigated by Density Function Theory (DFT) method.

Density functional method (DFT) has been combined with global minimum techniques into hy- brid schemes: The equilibrium geometries and electronic properties of little cluster Nbn (n=2～6) clusters were determined via DFT computations.

By using quantum chemical DFT methods,the high-spin moleculars with differ spin-containing fragment are designed using two neuter radicals by planar coupling unit.