Stabilization and Structure Calculations for Noncovalent Interactions in Extended Molecular Systems Based on Wave Function and Density Functional Theories

The development of faster QM procedures is highly important since we need to describe larger and larger fragments of bio- and nanostructures as accurately as possible. The very unique position of the CCSD(T)/CBS technique follows from the fact that it is the only theoretical ab initio procedure that provides accurate stabilization energies for various types of noncovalent complexes. The section on DFT should start with a brief discussion of the limitations of standard DFT functionals in the description of noncovalent interactions. Successes and failures of DFT in studies of H-bonded and stacked structures will be demonstrated on DNA base pairs and amino acid pairs. DFT-based methods are usually understood to be faster alternatives to WFT calculations. When corrected for the missing dispersion interaction, the accuracy of DFT in the field of noncovalent interactions is currently becoming acceptable for most modeling applications.