Topics

16

General Questions and Answers / Parallelization in ATK 13.8

« on: May 20, 2019, 17:44 »

I wanted to ask if parallelization is posssible in 13.8 version. I have followed all the steps in the old tutorial but my job manager still does not give any option for running in parallel.

17

General Questions and Answers / Transmission Spectrum vs bandstructure

« on: May 7, 2019, 16:47 »

Is is true that the number of bands crossing the fermi energy level should be equal to the transmission coefficient at fermi level?

18

General Questions and Answers / different transmission for unit cell and device

« on: May 7, 2019, 16:20 »

As per my knowledge, transmission spectrum for a perfectly periodic structure can be calculated just from the bulk material (unit cell) and does not need device setup. However, in order to see eigenvalues and eigen states device set up is necessary. I am trying to calculate transmission of carbon nanotubes adsorbed with metal chains. However, when I calculate the transmission spectrum using the unit cell bulk material it gives different values and when I set up device by repeating the same structure and converting it to device, it gives different values. Please guide me which one is the correct procedure to calculate transmission spectrum?

19

General Questions and Answers / k point sampling for optimization of unit cell

« on: April 19, 2019, 06:32 »

I want to optimize unit cell of carbon nanotube adsorbed with metal atoms. I know that for device calculation k point sampling is 1*1*many. However, for perfectly periodic system transmission spectrum can be calculated from bulk. I want to know what kind of k point sampling and constraints need to be given to optimize such a structure. Also is it correct to optimize unit cell, repeat it along transport direction, convert to device and calculate transmission spectrum without any further device relaxation?