Topics

1

General Questions and Answers / trouble with calculating transmission

« on: January 21, 2011, 03:12 »

I get the error

 Back Engine Exception 92 : Too large a difference in calculated transmissions has been detected among processes
** Location : calculatetransmissioncoefficient.cpp:164

any ideas what i did wrong?

this is my script

Code

from NanoLanguage import *
from numpy import *

configuration = nlread("CGsupergap.nc", object_id="gID000")[0]



#setup energies, and calculate DOS
x1= numpy.linspace(-1,1,20)
x2= numpy.linspace(-0.628,-0.622,15)
x3= numpy.linspace(0.27,0.31,10)
energies= numpy.hstack((x1,x2,x3)) * eV
dos = TransmissionSpectrum(configuration, energies=energies,kpoints=MonkhorstPackGrid(1,1,1),
energy_zero_parameter=AverageFermiLevel,
infinitesimal=1e-06*Units.eV,
self_energy_calculator=KrylovSelfEnergy() )

dos1 = DeviceDensityOfStates(configuration, energies=energies,
kpoints=MonkhorstPackGrid(1,1,1),
    contributions=All,
    energy_zero_parameter=AverageFermiLevel,
    infinitesimal=1e-06*eV,
    self_energy_calculator=KrylovSelfEnergy())

nlsave('CGsupergap.nc', dos)
nlsave('CGsupergap.nc', dos1)

2

General Questions and Answers / LDOS ATK 11.2 alpha version

« on: January 16, 2011, 00:21 »

Hi,

Can I use old .nc from 10.2 to calculate the LDOS with the new alpha version? I tried and I get some pictures I dont really understand. I thought it would be similar to results i got with atk 2008.

3

General Questions and Answers / mulliken population

« on: December 23, 2010, 00:52 »

Is there a way to use the projection list mulliken_population = MullikenPopulation(configuration=configuration) like mpsh function?

4

General Questions and Answers / workfunction new ATK

« on: November 17, 2010, 07:27 »

I want to calculate the work function, can I calculate it the same way it was calculated in atk2008? I tried and I get 4.037 eV

5

General Questions and Answers / 3d viewer

« on: October 21, 2010, 21:17 »

I want to plot few atoms as ball and stick  and the rest of my atoms i want to just plot the bonds. All the atoms are in the central I want to pick and choose which one are plotted and a certain way. Can VNL do this? if not does anyone know a program that can?

Jacob

6

General Questions and Answers / bloch states

« on: October 7, 2010, 20:57 »

My Bloch states for my gamma point look great, thanks 

For non gamma points where the Bloch function can be real (R) and imaginary (I), my graphs seem a little off. Does ATK 10.8.2 plot both R and I? If so is there a way to just plot the R?


Also is there a way to just use two colors in the plotting one for majority spin and one for minority?

7

General Questions and Answers / Atk 10.8 and 10.8.1

« on: October 6, 2010, 04:50 »

It seems my DOS has 25 or more states/energy in 10.8.1 as compared to 10.8?


any suggestions

8

General Questions and Answers / adding LDOS

« on: October 1, 2010, 14:04 »

Can LDOS be added like effective potential?

9

General Questions and Answers / relaxing

« on: September 30, 2010, 21:43 »

I figure that the relaxation uses a conjugate gradient method?

10

General Questions and Answers / Energy convergence?

« on: September 26, 2010, 09:41 »

|  59 E = -189.328 dE =  2.454780e-05 dH =  7.548698e-03                       |
|  60 E = -189.328 dE =  3.439094e-05 dH =  4.037563e-03                       |
|  61 E = -189.328 dE =  3.385915e-05 dH =  2.632685e-03                       |


61 is the last step of my equivalent bulk but the energy criterion is 4e-5 any suggestions?

11

General Questions and Answers / question with script

« on: September 25, 2010, 17:14 »

I try this script from the manual and i get the error, AttributeError: 'list' object has no attribute 'shape'

Code

transmission_spectrum = TransmissionSpectrum(
configuration=device_configuration,
energies=numpy.linspace(-0.5,0.5,10)*eV,
kpoints=MonkhorstPackGrid(3,3,1),
energy_zero_parameter=AverageFermiLevel,
infinitesimal=1e-06*Units.eV
)
# Print out all k-dependent transmission coefficients
data = transmission_spectrum.transmission()
energies = transmission_spectrum.energies()
kpoints = transmission_spectrum.kpoints()
for i in range(data.shape[0]):
print 'Transmission at energy = %12.6f eV' % (energies[i].inUnitsOf(eV))
print ' kx ky transmission '
for j in range(data.shape[1]):
print '%10.4f %10.4f %16.6e' % (kpoints[j][0],kpoints[j][1],data[i][j])
print

12

General Questions and Answers / 64 bit windows

« on: September 23, 2010, 22:08 »

I installed the 64-bit version but i double click and nothing happens. however i installed the 32-bit version and it works fine.

13

General Questions and Answers / Any suggestions?

« on: September 21, 2010, 19:13 »

Code

Center = 172, Left = 222


** Back Engine Exception 29 : central and left electrode has different grid size in i direction
** Location : electrodeutils.cpp:126

I guess i have to choose the same mesh for my CR and my electrodes.

14

General Questions and Answers / memory?

« on: September 15, 2010, 21:54 »

Question?
I am running similar systems, one with smaller leads and less surface layers. About 100 atoms are taken out of the central region and the mesh cuttoff is 80 Ryd for both. However both systems use the same amount of memory.

15

General Questions and Answers / Density Matrix Constraint

« on: September 15, 2010, 18:38 »

How does one use the density matrix constraint, with the electrode lengths for atk 10.8.