Messages

1

General Questions and Answers / Re: The direction of effective mass analysis

« on: August 18, 2023, 21:42 »

Thank you very much.

So if i want to calculate the effective mass in the direction of the armchair and the zigzag, I just need to fill in the Cartesian coordinates of (0, 1, 0) and (1, 0, 0). It is a very simple question, but I still want to confirm it.

Thank you again.

2

General Questions and Answers / Re: The direction of effective mass analysis

« on: August 16, 2023, 09:18 »

This is the k-points of the cell in the article and bandstructrue.

3

General Questions and Answers / The direction of effective mass analysis

« on: August 16, 2023, 09:07 »

Hi, everyone

I saw that the two directions for calculating the effective mass in this tutorial are (101) and (110), and I think 101 is due to the fact that the X point is (1/2 0 1/2) in the article High-throughput electronic band structure calculations: Challenges and tools (DOI: 10.1016/j.commatsci.2010.05.010), but I can't understand the choice of the other direction, because the effective mass is related to the bandstructrue., so I think we should take the coordinates of the point L,since it is another point close to Γ. So it's 1/2, 1/2, 1/2 in fractional coordinates, it's 1, 1, 1.

 If I understand wrong, please point out my problem, I will be very grateful.Thank you very much.

4

General Questions and Answers / Re: Mulliken Population analysis

« on: June 27, 2023, 04:38 »

Thank you for your help.

If I want to calculate the net charge of some of these atoms, what should I do?(i.e. the net charge of designated region)

Wish you have a nice day!

I think you are mixing up total charge and net charge. The "sum" version gives the sum of the differences of the Mulliken charges and the neutral atom charges (i.e. the net charge of the central region), but summing manually just gives you the total Mulliken charges (total number of electrons in the central region).

5

General Questions and Answers / Re: Mulliken Population analysis

« on: June 26, 2023, 05:03 »

Not just these two atoms in the picture, incomplete

6

General Questions and Answers / Mulliken Population analysis

« on: June 26, 2023, 04:56 »

Hi, everyone

I saw in this topic that you can use 'MullikenPopulation.atomicCharge().sum()'  to calculate the total charge of the device.
https://forum.quantumatk.com/index.php?topic=7116.msg29196#msg29196

However, for the same mulliken population, the manual sum and the .py give a different magnitude of data, the .py gives a result of about a few tenths of e, and the manual sum of this total is more than that. What is the unit manually added, is there any conversion relationship in it, or should the value of total not be added?

Thank you for your answer.

7

General Questions and Answers / doping concentration in FET S/D

« on: November 21, 2022, 02:56 »

Dear QuantumATK staff

I want to calculate the IV of FET device using IVCharacteristics object. However, the result circuit is either too large or small. I think it is because of the wrong doping concentration. So, i want to know that before calculating the IVCharacteristics object, what can i do to help me find the proper doping concentration. For example, by calculating the PDOS or bandstructure.

Any help from someone who knows the answer would be really appreciated.
Thank You.