Changing shape under pressure: a computational study of semiconductor nanocrystals by metadynamics

Add to your list(s) Download to your calendar using vCal

• Dr Carla Molteni, Kings College
• Thursday 22 October 2009, 14:00-15:00
• Theory Library.

If you have a question about this talk, please contact Dr Dimitri M Gangardt.

Pressure can be used as a tool for inducing structural transformations between distinct crystalline and/or amorphous phases. Polymorphism and polyamorphism phenomena can be studied by means of constant-pressure molecular simulations in both bulk- and nano-materials. In particular semiconductor nanocrystals exhibit, under pressure, a range of interesting size-dependent properties, which need to be dealt with specific techniques for non-periodic systems. Still constant pressure molecular dynamics simulations for structural phase transformations suffer from shortcomings due to the limited accessible time-scale that result in the need of overpressurizing the system under investigation in order to see the transformations within a reasonable time. To address such problem, we use the metadynamics method, which has proven to be very successful in accelerating rare events and in efficiently exploring free energy surfaces of complex polyatomic systems. Results for cadmium selenide and silicon bulk- and nano-crystals will be presented, highlighting in particular the role of shape in structural phase transformations.

This talk is part of the Theoretical Physics Seminars series.

This talk is included in these lists:

• Bham Talks
• Theoretical Physics Seminars
• Theory Library
• What's on in Physics?

Note that ex-directory lists are not shown.