Author Topic: How to calculate the charge transfer?  (Read 6643 times)

0 Members and 1 Guest are viewing this topic.

Offline hol28

  • Regular QuantumATK user
  • **
  • Posts: 15
  • Reputation: 0
    • View Profile
How to calculate the charge transfer?
« on: August 6, 2012, 03:00 »
Hi everyone:
In this topic, http://quantumwise.com/forum/index.php?topic=369.0, the author calculated the charge transfer in the system. I'm also studying the effect of the gate voltage on the charge of the central region in a two-probe system. I know that the mulliken population can give the charge of an given atom. Is there another way to calculate the charge transfer?
Any advice would be appreciated!

Offline mads.engelund

  • Heavy QuantumATK user
  • ***
  • Posts: 29
  • Reputation: 0
    • View Profile
Re: How to calculate the charge transfer?
« Reply #1 on: August 9, 2012, 09:21 »
Hmm, an alternative to the Mulliken population could be using the ElectronDensity. A rough example I have made:
Code
ed = nlread('analysis.nc', ElectronDensity)[0]
cut = 20
s = ed[:, :, :].sum()
print ed[:,:, :cut].sum()/s
print ed[:,:, cut:].sum()/s
Where 20 is some grid number in the z-direction. Also take a look at the manual entry for ElectronDensity :)

Offline hol28

  • Regular QuantumATK user
  • **
  • Posts: 15
  • Reputation: 0
    • View Profile
Re: How to calculate the charge transfer?
« Reply #2 on: August 28, 2012, 16:51 »
Thank you very much! I will have a try.
Hmm, an alternative to the Mulliken population could be using the ElectronDensity. A rough example I have made:
Code
ed = nlread('analysis.nc', ElectronDensity)[0]
cut = 20
s = ed[:, :, :].sum()
print ed[:,:, :cut].sum()/s
print ed[:,:, cut:].sum()/s
Where 20 is some grid number in the z-direction. Also take a look at the manual entry for ElectronDensity :)

Offline esp

  • Supreme QuantumATK Wizard
  • *****
  • Posts: 318
  • Country: us
  • Reputation: 3
    • View Profile
    • University of Minnesota
Re: How to calculate the charge transfer?
« Reply #3 on: November 4, 2012, 06:02 »
 I am going to try this as well .. question .. if have a 16nm long 2 probe GNR device, and i want to calculate the charge in the channel, would it be quicker in terms of computation time run the mulliken pop calc or the electron density calc?
« Last Edit: November 4, 2012, 06:09 by esp »

Offline Nordland

  • QuantumATK Staff
  • Supreme QuantumATK Wizard
  • *****
  • Posts: 812
  • Reputation: 18
    • View Profile
Re: How to calculate the charge transfer?
« Reply #4 on: November 4, 2012, 08:59 »
If you want to calculate the charge in a region, the only measure is the electron density, and it is not much slower than the mulliken population.