## DFD | DAMP | DAMPDSP
| ||||||||||||||||||||||||||

Synopsis
| ||||||||||||||||||||||||||

| ||||||||||||||||||||||||||

Description
| ||||||||||||||||||||||||||

This keyword specifies the damping function to be used for the calculation of atom-atom dispersion energies. The following damping functions are available:
The parameter | ||||||||||||||||||||||||||

Aim
| ||||||||||||||||||||||||||

The need for a damping function arises from the fact that the dispersion energy behaves as | ||||||||||||||||||||||||||

Remarks
| ||||||||||||||||||||||||||

Liu and Goddard III pointed out that the MDDRE, EHFSK and WY damping functions can be represented by a single formula with different choice of parameters [8], as shown in the following Table.
The four damping functions (MDDRE, EHFSK, WY, and TT) are shown in the left figure, along with their effects on the It appears that the damping strength by EHFSK function is between those by funtions MDDRE and WY, with WY function being the strongest. | ||||||||||||||||||||||||||

Related Keywords
| ||||||||||||||||||||||||||

| ||||||||||||||||||||||||||

References
| ||||||||||||||||||||||||||

*"Transferable ab initio intermolecular potentials. 1. Derivation from methanol dimer and trimer calculations"* W.T.M. Mooij, F.B. van Duijneveldt, J.G.C.M. van Duijneveldt-van de Rijdt, B.P. van Eijck
*J. Phys. Chem. A***1999**,*103*, 9872-9882.*"Empirical correction to density functional theory for van der Waals interactions"* Q. Wu, W. Yang
*J. Chem. Phys.***2002**,*116*, 515-524.*"Hydrogen bonding and stacking interactions of nucleic acid base pairs: A density-functional-theory based treatment"* M. Elstner, P. Hobza, T. Frauenheim, S. Suhai, E. Kaxiras
*J. Chem. Phys.***2001**,*114*, 5149-5155.*"Accurate Description of van der Waals Complexes by Density Functional Theory Including Empirical Corrections"* S. Grimme
*J. Comput. Chem.***2004**,*25*, 1463-1473.*"Semiempirical GGA-Type Density Functional Constructed with a Long-Range Dispersion Correction"* S. Grimme
*J. Comput. Chem.***2006**,*27*, 1787-1799.*"Density Functional Theory Augmented with an Empirical Dispersion Term. Interaction Energies and Geometries of 80 Noncovalent Complexes Compared with Ab Initio Quantum Mechanics Calculations"* P. Jurecka, J. Cerny, P. Hobza, D. R. Salahub
*J. Comput. Chem.***2007**,*28*, 555-569.*"An improved simple model for the van der Waals potential based on universal damping functions for the dispersion coefficients."* K. T. Tang, J. P. Toennies
*J. Chem. Phys.***1984**,*80*, 3726-3741.*"A Universal Damping Function for Empirical Dispersion Correction on Density Functional Theory"* Yi Liu, W. A. Goddard III
*Materials Transactions***2009**,*50*, 1664-1670.
| ||||||||||||||||||||||||||