Seminar 5th May 2010 1:20 p.m. Building 29, main lecture theatre
Finding infrequent events with MD: crystal nucleation, growth and biomineralisation
Professor P. Mark Rodger
University of Warwick
- Categories
- Biomolecular simulations
- Submitter
- Syma Khalid
The use of biomolecules in nature to direct the path of crystal growth leads to a degree of polymorph and morphology control that far surpasses anything that can currently be effected in a laboratory. Important and topical examples include the intricate nano- and micro-crystalline structures found in mollusc shells, coccoliths and avian eggshells. An ability to model the onset of crystal formation at a molecular level would considerably enhance our ability to understand, and potentially to mimic, how such exquisite control of crystal form is brought about; unfortunately, the timescales on which crystal nucleation occurs is much longer than the timescales accessible to standard molecular simulation methods. However, a number of recent developments in molecular simulation methods have begun to change this, so that routine, direct molecular simulations of the critical stages of crystal nucleation are becoming feasible for many systems. In this talk we will show how the “metadynamics” method can be adapted to simulate the onset of crystal formation with statistical reliability, to extract rigorous thermodynamic information about the nucleation process and to characterise how chemical additives can modify the nucleation and subsequent growth. Several examples of applications of the method will be given, including spontaneous formation of ice in constant pressure simulations, crystal formation from amorphous calcium carbonate, calcite formation on SAMS and the role of ovocleidin-17 (a protein found in the chicken eggshell) in the eggshell formation.