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QuantumATK => General Questions and Answers => Topic started by: huiju on October 7, 2021, 15:50

Title: Peak of Density of State
Post by: huiju on October 7, 2021, 15:50

Hi, I'm a beginner using Quantum ATK.

I want to get some density of state plots, but it shows very broad peak.
Is there a some setting or method to get a sharp peak in DOS(density of state)?
For your reference, I attach the image of CNT(7,0) density of state that I got.

Thanks.
Best regards,
Huiju Lee

Title: Re: Peak of Density of State
Post by: mlee on October 8, 2021, 13:51

You can plot the DOS spectrum with two different methods. There is an option to select the Gauissian or tetrahedron spectrum, but the current version doesn't include it in the GUI.
See https://docs.quantumatk.com/manual/Types/DensityOfStates/DensityOfStates.html#densityofstates-c

You can plot it such as the below one:

# read DOS object from file
dos = nlread('CNT70.hdf5', DensityOfStates)[0]

# make list of energies
energies = numpy.arange(-14,5,0.01)*eV

# calculate the DOS spectrum with two different methods
dos_t = dos.tetrahedronSpectrum(energies)
dos_g = dos.gaussianSpectrum(energies, broadening = 0.2*eV)

#plot the spectra using pylab
import pylab
pylab.figure()
pylab.plot(energies.inUnitsOf(eV), dos_t.inUnitsOf(eV**-1))
pylab.plot(energies.inUnitsOf(eV), dos_g.inUnitsOf(eV**-1))
pylab.xlabel("Energy (eV)")
pylab.ylabel("DOS (1/eV)")
pylab.show()