Dear Siesta users, I study silicon slab, centrosymmetric (no hydrogen). Thickness is about 15 Ang. Now I want to find such vacuum space that Etot is converged.
But it converges until a value of about Etot=-9252.4480 (at Hvac=10 Ang), but with further increase of vacuum space Etot increase/decrease (fluctuates) around this value by 0.0005 eV (see the graph attached). Is it normal? Why this happen? Why Etot does not converge to some exact value as expected? Kind regrads Ruslan Zhachuk
<<attachment: graph.PNG>>
