Ideal gas pressure bath: a method for applying hydrostatic pressure in the computer simulation of nanoparticles

Abstract

We present a method for applying hydrostatic pressure in the computer simulation of nanoparticles, using an ideal gas as the pressure medium and thermostat. As the equation of state is known for the ideal gas, the exerted pressure can easily be tuned by adjusting the number of gas particles, while the temperature is controlled by their kinetic energy. Applying this method, we study the pressure-induced transformation from the four-coordinate wurtzite to the six-coordinate rocksalt structure in faceted CdSe nanocrystals. The transformation involves the consecutive sliding of parallel (100) planes and proceeds through a five-coordinate intermediate structure.

Keywords:

• Nanoparticles; Computer simulation; Hydrostatic pressure; Ideal gas pressure bath

Acknowledgements

This work was supported by the Austrian Science Fund (FWF) within the Science College ‘Computational Materials Science’ under grant No. W004.