QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: Anurag Gaur on May 22, 2015, 08:45

Title: calculating oscillating frequency of a molecule.
Post by: Anurag Gaur on May 22, 2015, 08:45

hello friends,
I wish to calculate the oscillating frequency of a carbon nano ribbon but am not able to figure out how to do it on ATK.
Also,  is it possible to add an AC voltage source to any device/system on ATK...??????

 Please respond to my post  as earliest as possible.
Thank you...!!!!

Title: Re: calculating oscillating frequency of a molecule.
Post by: zh on May 25, 2015, 03:08

You can use a supercell with a large size to model the molecule and then perform the calculation of the dynamical matrix as well as the phonon. In this case, the calculations of the phonon density of states will give some information about the vibration frequencies of molecule.

It is impossible to add an AC voltage in the simulation of any device by using ATK.

Title: Re: calculating oscillating frequency of a molecule.
Post by: Anders Blom on May 25, 2015, 09:41

Not completely impossible, but it requires a bit of work.
See http://quantumwise.com/documents/tutorials/latest/LowLevelEntities/index.html/chap.acconductance.html

Title: Re: calculating oscillating frequency of a molecule.
Post by: Anurag Gaur on May 25, 2015, 14:52

Thanks for the reply Anders,
Actually i wish to input some sinusoidal signal to my device and not derive it from ATK simulations.
How to add this source?
Please help.
Thanks in advance. :)

Title: Re: calculating oscillating frequency of a molecule.
Post by: Anders Blom on May 26, 2015, 06:44

No idea, probably not so easy. What ATK can do is give you the Green's functions and other stuff, for the rest you are on your own :)