> On Sun, Apr 18, 2010 at 5:34 PM, Руслан Жачук <[email protected]> wrote: > >> I use Siesta-2.0.2. I need to calculate surface formation energy very >> precise. >> But these fluctuations produce errors well below 0.1 meV/Ang2 so I am >> satisfied. >> > > You mean per atom? Because, in absolute values, you have 0.5 meV/Ang. >
The studied slab is 3x3 surface unit cell with area about 100 Ang^2. Fluctuations of Etot for this slab is 0.5 meV. Esurf is calculated as ususal Esurf = Etot - uN (u - chemichal potential, N - number of atoms) Therefore estimated error in Esurf due to these fluctuations is 0.5/100 = 0.005 meV/Ang^2 Seincerely Ruslan
