Meetings

WG4 Theory Meeting, 19-22nd April, Nottingham, UK


The meeting was organised by Elena Bichoutskaia (WG4 leader) at the Chemistry Department in Nottingham University.
Presentations covered a mix of exciting developments in new theoretical techniques in quantum chemical atomistic modelling, and groups presenting applications of these techniques to nanoscale problems.
Unfortunately the period coincided with the volcanic eruption in Iceland which blocked travel plans for many of the attendees, notably those from further away in Europe such as Turkey, Greece, Portugal, and Switzerland.  Nonetheless the attendance was good (even if many attendees arrived later than initially planned), with modified travel plans including buses, boats, coaches, trains, ...

The “applications” talks included many on studies of graphene and graphene interfaces (gas absorption, redox chemistry on graphene surfaces, folding and defect formation), behaviour of silicon quantum dots and the effect of chemical functionalisation of their surface on their electronic behaviour, radiation damage and oxidation in carbon based materials, correct modelling of TiOx based materials and surfaces (notably for gas absorption), … Two things were particularly noticeable – the diversity of problems being tackled, yet the similarity in approaches often used.  This led to a great deal of dynamic and stimulating debate, often throughout the talks, leading to clear guidelines for ‘best practise’ for simulation of different problem types.  There were also clear suggestions from the applications modelling groups concerning areas of current difficulty where further methodological developments were necessary, notably for accurate modelling of exchange energy, a better description of Van der Waals forces (and extraction of any erroneous VdW correction terms in current functionals such as the local density approximation for exchange and correlation), and as always, increased code speed.  Many different theoretical approaches were presented, primarily running AIMPRO but also alternative codes such as Quantum Expresso, making for very interesting benchmark and comparative studies.

The other section of talks concerned recent developments in theoretical methodologies.  These represented some particularly exciting and ground breaking steps forward, likely to have a major impact on the theoretical modelling performed during the 4 years of NanoTP, and it is not overstating to say that, once fully bug tested and distributed, some of the new code improvements will represent the biggest change in modelling for around ten years.  New filtration techniques have been developed, allowing users to start with extremely large and precise basis sets, which are then dynamically reduced to contracted basis sets “on the fly” during calculation, allowing users to run calculations with potentially the accuracy of full plane wave runs, at speeds of around a thousand times faster (and a hundred times faster than are typical with the Gaussian codes).   This means users will be able to tackle new types of theoretical models, such as complex interfaces, low dimensional extended defects, and very low symmetry large molecular systems, which are beyond the capabilities of current quantum chemical first principles codes.  Both screened exchange and Van der Waals incorporation are also close to being finished and integrated into a new release of the code.

 

A “roll out” date for an updated version of AIMPRO was discussed and proposed for the end of the summer.  There were also discussions concerning a potential training session or workshop for the same period for new users, and the idea was raised of scheduling a formal NanoTP WG4 training workshop in 2011 to bring existing users up to date on the new functionality of the code, and introduce other members of NanoTP to the code and approach.

 

A brief presentation of NanoTP was given by the vice-chair, Chris Ewels, including details of the STSMs and the application procedure to be followed.  There were several expressions of interest.  One WG4 member (Hugo Pinto) has also applied for a COST bursary to give an oral presentation at E-MRS in Strasbourg.

Participants were extremely grateful to COST for supporting the meeting, and there was consensus agreement that the meeting was extremely successful.  This was despite the formidable logistical difficulties associated with the last minute cancellations due to the volcano, which required continuous updating of the programme schedule throughout the meeting.  The organisers wish to thank Nottingham University for their support and understanding, particularly concerning the associated last minute cancellations of rooms.

Finally we would like to thank the local organiser, Elena Bichoutskaia, who worked tirelessly in the lead-up to the meeting, and throughout, to ensure its success.

Further details are available on the NanoTP internal website.


19 April 2010