DOS vs TS

[Jahanzaib]

Dear Expert
I have attached photo for my system where I have shown you DOS and TS. In DOS, there are some peak on the fermi level but in TS its not? I dont understand this? Is a way to make TS peaks smooter like DOS attached in pics or is there a way to add broadening in TS? I want TS peak a bit smoother.

Thank you

[Anders Blom]

You can easily increase the number of energy points in the transmission spectrum, but smoothing is probably not a good idea. The reason we smooth in the DOS is that we don't give the energy points as fundamental input but rather the k-points, and actually Gaussian smoothing is only applied if you have very few points, else we use the tetrahedron method (Phys. Rev. B, 49, 16223 (1994)) to interpolate.

[Jahanzaib]

Thank you Dr Blom.

The reason for using only a few k-points for the TS calculation in my case is that I have a very long stanene nanoribbon, which generally requires only a few k-points. In some cases, I observed a bigger peak in the DOS, but when I examined the transmission spectrum (TS) at zero bias for the same system, that peak was not present. To my understanding, the transmission function T(E), which can be considered a density of states (DOS) weighted by the probability of electron transfer from the device region to the left or right electrodes.

I think if I increase the number of k-points in the B direction only in stanene nanoribbon, I might observe similar peaks. For a 1D system like this, I assume that increasing k-points in the B direction should be fine??

[Anders Blom]

I didn't say use more k-points for the transmission, you should use more energy points.