C-V curve of a device

[Hesam]

Is it possible to simulate C-V curve (capacitance versus voltage) using ATK? Or it is possible to do some post process with the simulation results to do that?

[kstokbro]

Yes, it is possible, you can find a tutorial here:
http://www.quantumwise.com/publications/tutorials/mini-tutorials/203

[Anders Blom]

What you mean is perhaps slightly different from a conceptual perspective, even if a similar simulation technique can be used as in the mini-tutorial mentioned. You can perform a simulation similar to that in http://quantumwise.com/documents/tutorials/latest/GrapheneDevice/index.html/ and vary the gate potential, and for each simulation compute the induced net charge below the gate from the Mulliken populations, that gives you an estimate of C. This can be done for nanowires, 2D FinFETs, etc.