I want to calculate the formation energy
of WS2 monolayer unit cell using VASP
. I am wandering if you could show me the detailed calculation steps in VASP
to do that for WS2 or any monolayer.
1 Answer
I am not sure whether there is a special point about monolayer. The steps to calculate the formation energy are following (This is suitable for bulk materials):
- Calculate the total energy of primitive monolayer WS2: $E$(WS2)
- Calculate the total energy per atom for the lowest-energy configuration bulk S: $E$(S)
- Calculate the total energy per atom for the lowest-energy configuration bulk W: $E$(W)
- Estimate the formation energy: $$\Delta E_f=E(\text{WS2})-\dfrac{1}{3}E(\text{W})-\dfrac{2}{3}E(\text{S}).$$
Reference paper: https://www.sciencedirect.com/science/article/abs/pii/S0966979509000892
Hope it helps.
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$\begingroup$ I am wandering if you could just show me how calculate the total energy per atom for the lowest-energy configuration bulk "S and W". Should I do relaxation then SCF ? Which structure should I put for bother "S and W" ? Thanks in advance, and you were helpful as always. $\endgroup$– Chi KouFeb 21, 2021 at 6:56
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2$\begingroup$ @ChiKou S: materialsproject.org/materials/mp-96 . W: materialsproject.org/materials/mp-91 $\endgroup$– JackFeb 21, 2021 at 22:44