TOMBO Ver.2 Manual
TOMBO
TOMBO
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1.4 Calculation flow 10<br />
1.4 Calculation flow<br />
Flowchart of the first-principles molecular dynamics (MD) is shown in Fig. 1.5.<br />
Set initial atomic positions<br />
❄<br />
Assume initial charge density<br />
❄<br />
Initialize coefficients C λ i<br />
✲<br />
❄<br />
Calculate charge density<br />
❄<br />
Mix the charge density with<br />
that of the previous step<br />
Calculate the KS potential<br />
❄<br />
Calculate matrix ❄ elements<br />
❄<br />
Update Ci<br />
λ according to<br />
matrix diagonalization or<br />
steepest-descent method<br />
❄<br />
NO ✘✘✘✘✘✘✘<br />
✛ ✘❳❳❳❳❳❳❳❳❳❳❳❳❳❳❳❳❳❳<br />
✘ If |E new − E old | < precLDA<br />
✘✘✘✘✘✘✘✘✘<br />
YES<br />
❄<br />
Calculate forces on atoms<br />
❄<br />
Update atomic positions<br />
Check self-consistency<br />
Fig. 1.5 Flowchart of the first-principles MD. The convergence of the electronic states is<br />
checked by the difference between the total energies at the present and previous steps. If<br />
convergence is achieved, the atomic positions are updated by using the calculated force.