QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: manishk19 on February 2, 2018, 17:24

Title: ZAlNNR
Post by: manishk19 on February 2, 2018, 17:24

Hello sir,
I have made hydrogen passivated zigzag AlN nanoribbon of width 3 Al atomes using the plugin and optimized it. The band gap is 2.78eV (as given in the paper"Electronic and magnetic properties of Cd-doped zigzag AlN nanoribbons from first principles" DOI 10.1007/s12598-015-0471-z), but I am getting 4.03517eV in ATK VNL. Please tell me what is the problem

Title: Re: ZAlNNR
Post by: manishk19 on February 4, 2018, 12:53

please give some answer

Title: Re: ZAlNNR
Post by: Petr Khomyakov on February 5, 2018, 13:45

I guess the first thing is to check if the structure of your device is the same as in the reference paper. The second thing is that you have to use the computational settings (density functional, k-point sampling) for DFT calculations that are similar to that in the paper, and also do convergence tests with respect to basis set and density mesh cut-off.

Note that the paper uses all-electron code to do the DFT calculations, whereas QuantumATK makes use of norm-conserving  pseudopotentials, treating core electrons with an effective potential (called pseudopotential). So that you might need using accurate pseudopotentials such as SG15.