  In this chapter, by using ab-initio molecular dynamics, we introduce the
latest simulation results on two materials for flash memory devices: Ge2Sb2Te5
and Ge-Se-Cu-Ag. This chapter is a review of our previous work including some
of our published figures and text in Cai et al. (2010) and Prasai & Drabold
(2011) and also includes several new results.
