Ab initio molecular dynamics: recent progresses and limitations

I will discuss recent developments in ab initio molecular dynamics (MD) based on the density functional theory (DFT). Presently, most such calculations are performed using the pseudopotential approximation. With the introduction of the projector augmented-wave method, the exact valence wave functions can be applied during MD without worsening the efficiency of the calculations significantly. Hence, calculations are now exact at least in the framework established by DFT. This allows attention to be turned to other limitations, such as system size or the present semilocal approximations used in DFT. I will show results of a comprehensive study for the liquid metallic (and semiconducting) p elements Al, Ga, In, Tl, Si, Ge, Sn, Pb, As, Sb, Bi, Se and Te. Compared to experiment, discrepancies in the structure factor are observed in particular for heavy elements and for As, Se and Te. Possible reasons for these discrepancies are discussed.