RESEARCH - SIMULATIONS

Charge transfer in 1,000 molecules of Rubrene

A visualisation of hole transport in a plane of 1,000 Rubrene molecules. Dynamics were carried out using fragment-orbital based surface hopping. A non-adiabatic molecular dynamics technique. The gray objects are Rubrene molecules, the blob is a visualisation of the electron-hole wavefunction.

Non-adiabatic molecular dynamics simulation of electron hole transport in crystalline pentacene at 200K

Calculated change in charge distribution in an oligomer:fullerene pair

"Calculated change in charge distribution between g.s. and first to third excited states in an oligomer:fullerene pair. Electron density moves from red to blue regions. Degree of charge transfer and excitation energies are also indicated for each transition." Sheridan Few, Jenny Nelson

One nanosecond simulation of a cluster of one sulphuric acid and six water molecules

The movie shows a one nanosecond simulation of a cluster of one sulphuric acid and six water molecules. The Empirical Valence Bond (EVB) methodology was employed within a modified version of DL-POLY 4.0.3 such that proton transfer could occur within the system. If a hydrogen atom leaves the sulphuric acid species it is coloured blue making it is possible to follow its trajectory through the water network. Whilst in the water network the hydrogen atom is known as an excess proton. The grotthuss mechanism is observed in the simulation where the mobility of the excess proton is enhanced by its ability to eject one of the other two hydrogen atoms within the water molecule to which it is attached.

Credits: Jake Stinson: UCL, LCN, TYC, London;  Ian Ford: UCL, LCN, TYC, London;  Shawn Kathmann: Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States.