• Atomistic simulations provide models to underpin the interpretation of experimental data.
• In certain fields, referees systematically ask for simulation results to provide models e.g. phonon calculations in the case of a mainly experimental paper currently with PRL
• I expect simulations to improve the quality of publications rather than the number.
• For example, experimental results from D4 on Ge-Te liquid alloys were published in Phys. Rev. B (67/104202). Three years later we published DFT simulations that gave quantitative insight into these results in Phys. Rev. Lett. (95/267801). Now, with C-Lab, experiment and simulation would be published directly in PRL. Also there are currently papers submitted to Nature (past the editor) and Nature Materials (invited, following an award as best conference contribution), both combining INS powder data and DFT-based molecular dynamics and phonon calculations.
• There have also been a couple of examples of diffraction work where data could not be Rietveld refined because reasonable starting structures were not available. Simulations provided adequate initial structures e.g. organics – Chem. Phys. 333/236, metal oxides – J. Solid State Chem 177/1838, adsorption on nanotubes – PRL 91/35503 & 95/185302. In these cases the experimental data would not have been published without input from simulations, but the value of the finished product is the combination of experiment and simulation.

8 people in addition to contributions from CS (Johnson, Gonzalez, Farhi)

Post-docs:

• Eric Pellegrini, ANR Orleans – Soleil – ILL project, since November 2007
• Lucia Capogna, CNR – Italy funding, since January 2005

Long term visitors:

• Viviana Cristiglio, funded by Montpellier (ANR project on ion conducting chalcogenide glasses) from April 2008 for one year.
• Delores Ruiz-Martin, funded by ETSEIB, Uni Barcelona (project: structure and dynamics of molecular liquids) from April 2008 for two years.

Thesis students:

• Emanuela Pusceddu, collaboration with CNR (Claudia Mondelli), project: ordering phenomena in half-doped manganites
• Stefan Eibl, collaboration with Orsay (Christiane Alba-Simionescu) and TOF (Helmut Schober, Marie Plazanet) project: structure and dynamics of a fragile molecular glass, since January 2007
• Bachir Aoun, collaboration with Orleans (Marie-Louise Saboungi), project: structure and dynamics of ionic molecular liquids, since October 2007.

• Proteus/Egide funding for collaboration with Franci Merzel, National Institute of Chemistry, Slovenia
• UK EPSRC project with Ivana Evans, Durham, accepted (Autumn 2007), post-doc shared between Durham and ILL

Our simulation tools are classical, atomistic MD and DFT (quantum chemistry). The former allow time and length scales of neutron scattering experiments to be matched by simulation. The latter allow smaller systems to be studied with higher accuracy by  MD or phonon methods and details of electronic and magnetic structure to be investigated.

We have strong activity in the structure and dynamics of disordered systems (liquids and glasses) and in the application of phonons to understand INS data from powders and to separate nuclear and magnetic signals.

New areas of activity are large scale simulations for bio-molecular dynamics (Katy Wood, Paolo Calligari and now Andreas Stadler) and the application of DFT to study magnetic (and related) ordering and interactions, which is driven by Mohamed Zbiri.

The following table is a list of projects on-going in the last year, some extend over several years. Independently of the proposal system there are typically ~15 projects started each year.

 glasses, liquids, amorphous diffraction, phonons

Structure problems

Phonons (INS)

Dynamics

• On the old ILL web-site, there were ~90 articles for the period 1995-2003.
• In the 3 years from 2005 to 2007, Miguel Gonzalez (25) and Mark Johnson (40) have 65 papers, nearly all being peer-reviewed and based on neutron and simulation data. Both of us are involved in wide range of projects, indicating the broad applicability of simulations and the service they can provide.
• Since 2000, the ILL Annual Report contains ~3 articles each year on “neutrons and simulations”.

The CS recently contributed in the organization of two workshops which both involved a significant contribution from simulations.

• DMM: dynamics in molecules and materials, Jan 2007
• SiMaDes: simulations and experiments in liquids and glasses, Jan 2008