# Density functional theory (DFT)

## Information obtained

- Most stable structure in solids and for fluids in contact with them
- Adsorption energies and geometries
- Bonding character
- Structural stability

## Principle

DFT solves the Schrödinger’s equation to obtain the ground state wavefunction of the system of interest. From this, electron density distribution of the system can be obtained, from which other properties can be derived.

# COSMO-RS — one approach to DFT predictions in solution

## Information obtained

- Solvation energies
- Partition coefficients
- Liquid-liquid interfacial tension
- pKa of acid and bases

## Principle

COSMO-RS combines the COSMO implicit solvent model and statistical thermodynamics. It can describe important interactions in a solvent, such as electrostatics, dispersion and hydrogen bonding. [1]

# Classical molecular dynamics (MD)

## Information obtained

- Time evolution of a system
- Local structural properties of materials and how fluids interact
- Conformational sampling
- Surface diffusion

## Principle

Classical MD is a computational technique that follows the time evolution of a set of *N*-interacting atoms by integrating the equations of motion from classical mechanics. MD is a statistical mechanics method. It is a way to obtain a statistical ensemble with a set of configurations from which one can obtain average properties.

# References

- A. Klamt, F. Eckert, W. Arlt, in
*Annual Review of Chemical and Biomolecular Engineering, Vol 1.*(2010), vol. 1, pp. 101-122. - K.S. Keller, M.H.M. Olsson, M. Yang, S.L.S. Stipp in
*Langmuir*(2015), vol. Y, pp. XX-XX.