Kris's Research Notes

June 29, 2012

Memoization of Rates

Filed under: Implementation — Kris Reyes @ 4:38 am

In this note, we comment on an implementation detail that accounts for a 10x speed-up to a naive KMC implementation: memoization of rates. Memoization is the act of storing rates computed in the course of the simulated so that they do not have to be re-computed again if needed. We summarize why doing this makes sense in the KMC context and give two consequences of its implementation which improves both performance and memory usage.


June 15, 2012

3D Nanowires — Liquid Droplets

Filed under: Nanowire — Kris Reyes @ 12:31 pm

In 2+1 dimensions, KMC simulations tend to facet easily. This makes sense as more bonds nearest and next-nearest neighbor bonds occur in 2+1 dimensions. Indeed, on the diamond lattice used throughout our 3D simulations, an atom posses 4 nearest neighbor and 12 next-nearest neighbor bonds. If we wish to model nanowire growth by the VLS method, it is desirable for our liquid (which resides on the lattice) to not be faceted. In this note, we describe preliminary results in our search for the correct energy and temperature parameters that allow this to occur.