QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: xiaoteng on March 24, 2017, 11:16

Title: Transmission Pathways
Post by: xiaoteng on March 24, 2017, 11:16

Hi，
    How can I calculate the spin-dependent Transmission Pathways by ATK 2014.3？ At present， I can only get the sum  Transmission Pathways using this version.
    Would you be kind enough to show me some links or text representation about solving this problem by ATK 2014.3？

Title: Re: Transmission Pathways
Post by: Jess Wellendorff on March 24, 2017, 12:29

I think there is no other solution than upgrading to a newer version of ATK, where all kinds of spins are supported by TransmissionPathways: http://docs.quantumwise.com/manuals/Types/TransmissionPathways/TransmissionPathways.html (http://docs.quantumwise.com/manuals/Types/TransmissionPathways/TransmissionPathways.html)

Title: Re: Transmission Pathways
Post by: xiaoteng on March 27, 2017, 11:47

Some published papers have shown the spin-resolved transmission pathways by lower version，such  as 2013.8.
And would you offer us a Script file （.py）that could distinguish spin-up and spin-down？

Title: Re: Transmission Pathways
Post by: Jess Wellendorff on March 27, 2017, 13:42

You may not be able to plot the spin-resolved TransmissionPathways using the Viewer, but the Text Representation should give you the Up and Down components. You can also use a script to print the spin components (Spin.Sum, Spin.Up, Spin.Down, etc). Here is an example giving the Spin.Up component:

Code

pathways = nlread('transmissionpathways.nc', TransmissionPathways)[-1]
path = pathways.evaluate(spin=Spin.Up)
for p in path:
    print "%i --> %i: %.4e" % (p[0], p[1], p[3])

Instead of printing the component (which is p[3] in the above), you can write to a file for saving/plotting.
See also the ATK Manual: http://docs.quantumwise.com/manuals/Types/TransmissionPathways/TransmissionPathways.html (http://docs.quantumwise.com/manuals/Types/TransmissionPathways/TransmissionPathways.html)

Title: Re: Transmission Pathways
Post by: xiaoteng on March 27, 2017, 15:48

Thank you!
Could you help me to check and modify the script file？The .nc file that I got is still the total！

Title: Re: Transmission Pathways
Post by: Jess Wellendorff on March 27, 2017, 23:29

I think the NC file contains all the spin components you need, but the VNL Viewer may be able to show only the Spin.Sum component, simply because Viewer support for the Up and Down components was only recently implemented. Your script looks ok, but I would personally split it into 2 scripts; 1 for computing the transmission pathways, and 1 for reading+printing it. See attached scripts.