Chemistry with ADF

We present the theoretical and technical foundations of the Amsterdam Densi ty Functional (ADF) program with a survey of the characteristics of the cod e (numerical integration, density fitting for the Coulomb potential, and ST O basis functions). Recent developments enhance the efficiency of ADF (e.g. , parallelization, near order-N scaling, QM/MM) and its functionality (e.g. , NMR chemical shifts, COSMO solvent effects, ZORA relativistic method, exc itation energies, frequency-dependent (hyper)polarizabilities, atomic VDD c harges). In the Applications section we discuss the physical model of the e lectronic structure and the chemical bond, i.e., the Kohn-Sham molecular or bital (MO) theory, and illustrate the power of the Kohn-Sham MO model in co njunction with the ADF-typical fragment approach to quantitatively understa nd and predict chemical phenomena. We review the "Activation-strain TS inte raction" (ATS) model of chemical reactivity as a conceptual framework for u nderstanding how activation barriers of various types of (competing) reacti on mechanisms arise and how they may be controlled, for example, in organic chemistry or homogeneous catalysis. Finally, we include a brief discussion of exemplary applications in the field of biochemistry (structure and bond ing of DNA) and of time-dependent density functional theory (TDDFT) to indi cate how this development further reinforces the ADF tools for the analysis of chemical phenomena. (C) 2001 John Wiley & Sons, Inc.