First-principles calculations of large-scale semiconductor systems on the earth simulator

First-principles simulations of large-scale semiconductor systems using the PHASE code on the Earth Simulator (ES) demonstrate high performance with respect to the theoretical peak performance. PHASE, designed for vector-parallel systems like the ES, demonstrates excellent parallel efficiency. We simulated an arsenic donor in silicon using up to 8,000 atom unit cell. A sustained peak performance of 14.6 TFlop/s was measured on 3,072 processing elements, which corresponds to 59% of the theoretical peak performance. Preliminary results using 10,648 atom unit cell are also presented.