60 likes | 159 Views
PENN S TATE. Department of Mechanical and Nuclear Engineering. ReaxFF simulations of O 2 /O/H 2 O collisions with a Si 9 cluster. A.Rahnamoun and A.C.T. van Duin Department of Mechanical and Nuclear Engineering Pennsylvania State University.
E N D
PENNSTATE Department of Mechanical and Nuclear Engineering ReaxFF simulations of O2/O/H2O collisions with a Si9 cluster A.Rahnamoun and A.C.T. van Duin Department of Mechanical and Nuclear Engineering Pennsylvania State University AFOSR/Tight project teleconference, November 5 2012
Motivation • To evaluate the accuracy of the ReaxFF Si/O/H force field we plan to compare ReaxFF and DFT/MD trajectories for O2, O and H2O collision with small silicon clusters • Procedure • Si9 cluster was equilibrated at T=300K • O2, O and H2O molecules were put close to the Si9 cluster and equilibrated under center of mass constraints to provide continuous MD-simulations where we can very clearly see the collision from the potential energy vs. time-graphs • O2 , O and H2O molecules were directed towards Si9 clusters with an initial kinetic energy of about 0.6eV • Simulations were performed using an NVE-ensemble • 5 ps simulations
Conclusions • O2 and O impacts cause significant re-organization of Si-cluster due to local exothermic heating • ReaxFF simulations take about 1 minute • The simulations can be repeated at different impact angles and energies • The simulations can be repeated for SiO clusters • Limitations of DFT/MD for these simulations?