Calculation of defect density in MoS2 due to sulfur vacancy

[Manish95]

I have a 3x3 supercell of MoS2. I have removed the S atom from the center  I want to calculate the defect density so that in my simulation, I can match it to the sulfur vacancy defect density in exfoliated 2H MoS2. Any inputs on how can I calculate it?

[Petr Khomyakov]

I am not sure I understand the question. For your given structure, you have one defect per unit cell - this is the defect density. You may also define it as # of defects per volume, then the defect density = the number of defects / unit cell volume, in your case, = 1 defect / unit cell volume.

[Manish95]

"The distribution of the point defects is non-uniform across the sample surface, with their native concentration typically ranging from 5x10^12 to 5 x10^13 cm−2 values" (doi: 10.1038/srep29726). This is the surface defect density of exfoliated MoS2 on Au. I want a similar comparison in terms of defect density in units of cm-2 not in terms of defects per unit volume.

[Petr Khomyakov]

Then compute it per surface area.

[Manish95]

Ok. Got it