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Messages - heguangmeng

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1
Deer all,
I want to know the definition of fermi energy (Ef) in calculation,  are the calculation of Ef for all material  the same?  How can I compare the energy in different figures of densty of states if the original points are differnt material's Ef?
look forward to your reply

2
dear all
When we calculate a transmission of a device, the process shown in https://docs.quantumwise.com/tutorials/atk_transport_calculations/atk_transport_calculations.html is that "An ATK device calculation is performed in multiple steps. First, the electrode(s) and the central region are treated as (periodic) bulk systems, and the self-consistent electron density is calculated for each of them. The device calculation is then started, using the central region bulk electron density as an initial guess, and matching the electronic structure at the two electrode/central region boundaries to that of the electrodes. Finally, the self-consistent electronic structure of the central region is determined, and thereby of the full device. "
My questions are the method to  calculate the self-consistent electron density is  Hamiltonian matrices or other else? And the electrode will be calculated in the same method? Where can we set the intruct?
look forward to your reply



3
dear all
I want to know when I calculate device and use the analysis of total energy, how many layers of electrodes will be calculated in the device?  My device has 5 layers of central region on the left and right respectively and the cycle unit of electrode is 3 layers. I wonder  ATK will calculate 8 layers, or only calculate 5 layers just as bulk.
look forward to your reply.

4
General Questions and Answers / transmission pathway
« on: January 15, 2018, 10:29 »
Dear:
When I calculate the transmission pathway, I met a trouble. The situation is that: I know that Self-consistent wave function is calculated from left to right acquiescently. But when I gained the result. As to different contributions(right or left), the right ts pathways are more than left (you can see image, please).So I want to know what lead to the phenomenon. I think the transmission is an  scattering process. The left contributions and right contributions is equal. but left transmission pathways are more than right. And I want know the detail. Thanks!!!

5
when I use ATK to calculate the transmission of electron,I choose Co as the leads,but when I analyse the density of states of the isolated Co leads,I finally get a strange image as follows.That may contract to the fact.I wonder know why that happen.Hope you can answer my questions .

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