Messages

1

General Questions and Answers / can ATK consider the Coulomb interaction

« on: March 3, 2011, 03:07 »

Can ATK considered the Coulomb interaction or it has been considered?
The physics origin of magnetism is the Coulomb interaction, if it does not take the Coulomb interaction into account, how can we valid the calculated results?
My version is ATK 2008.10.
Thanks.

2

General Questions and Answers / how atk perform the MPSH?

« on: June 29, 2010, 09:26 »

hi, everyone
i know how to use atk to calculate the MPSH, but how atk deal with it?
can you offer me some references?

3

General Questions and Answers / Re: what's wrong?

« on: June 7, 2010, 15:27 »

The input file is attached. Thank you for your attention.

4

General Questions and Answers / what's wrong?

« on: June 6, 2010, 07:21 »

The TwoProbe Calculation show no energies?
# sc 18 : q =   95.81028 e  dRho =  9.7550E-02
# sc 19 : q =   95.79945 e  dRho =  1.1419E-02
# sc 20 : q =   95.82167 e  dRho =  4.5293E-03
# sc 21 : q =   95.71135 e  Etot =        inf Ry  dRho =  1.9420E-01
# sc 22 : q =   95.63542 e  Etot =        inf Ry  dRho =  1.9823E-01  dEtot =         NAN Ry
# sc 23 : q =   95.55492 e  Etot =        inf Ry  dRho =  2.7637E-01  dEtot =         NAN Ry
how to deal with that problem?

5

General Questions and Answers / Re: Geometry optimization

« on: May 25, 2010, 02:55 »

Thanks for your advice. I have set the cut off to 300Ry. I did not understand the mismatch you mentioned well. Did you mean that the less force should correspond a lower total energy? should i increase the energy criterion(i used 1e-4Ry yet) or increase the k-points?

6

General Questions and Answers / Re: Geometry optimization

« on: May 24, 2010, 14:45 »

Thanks~ the convergence detail are shown as follow:
# Geometry optimization step : 0
# Total Energy           =-16526.6212 eV
# Max Force Component    =     0.1047 eV/Ang
# Geometry optimization step : 1
# Total Energy           =-16526.6156 eV
# Max Force Component    =     0.0694 eV/Ang
# Geometry optimization step : 2
# Total Energy           =-16526.6072 eV
# Max Force Component    =    -0.3297 eV/Ang
# Geometry optimization step : 3
# Total Energy           =-16526.6231 eV
# Max Force Component    =     0.0708 eV/Ang
# Geometry optimization step : 4
# Total Energy           =-16526.5824 eV
# Max Force Component    =     0.7817 eV/Ang
# Geometry optimization step : 5
# Total Energy           =-16526.6247 eV
# Max Force Component    =     0.1687 eV/Ang
# Geometry optimization step : 6
# Total Energy           =-16526.4808 eV
# Max Force Component    =     1.6284 eV/Ang
# Geometry optimization step : 7
# Total Energy           =-16526.6205 eV
# Max Force Component    =     0.2656 eV/Ang
# Geometry optimization step : 8
# Total Energy           =-16526.5417 eV
# Max Force Component    =     1.4789 eV/Ang
# Geometry optimization step : 9
# Total Energy           =-16526.6236 eV
# Max Force Component    =    -0.1411 eV/Ang
# Geometry optimization step : 10
# Total Energy           =-16526.6103 eV
# Max Force Component    =     0.3657 eV/Ang
# Geometry optimization step : 11
# Total Energy           =-16526.6185 eV
# Max Force Component    =     0.2631 eV/Ang
# Geometry optimization step : 12
# Total Energy           =-16526.6095 eV
# Max Force Component    =     0.4792 eV/Ang
# Geometry optimization step : 13
# Total Energy           =-16526.5269 eV
# Max Force Component    =     1.0968 eV/Ang
# Geometry optimization step : 14
# Total Energy           =-16526.5349 eV
# Max Force Component    =     1.3849 eV/Ang
# Geometry optimization step : 15
# Total Energy           =-16526.6078 eV
# Max Force Component    =    -0.5014 eV/Ang
# Geometry optimization step : 16
# Total Energy           =-16526.6169 eV
# Max Force Component    =    -0.5166 eV/Ang
# Geometry optimization step : 17
# Total Energy           =-16526.6178 eV
# Max Force Component    =    -0.2461 eV/Ang
# Geometry optimization step : 18
# Total Energy           =-16526.6234 eV
# Max Force Component    =    -0.2057 eV/Ang
# Geometry optimization step : 19
# Total Energy           =-16526.6198 eV
# Max Force Component    =    -0.0938 eV/Ang
# Geometry optimization step : 20
# Total Energy           =-16526.6136 eV
# Max Force Component    =    -0.5022 eV/Ang
# Geometry optimization step : 21
# Total Energy           =-16526.6240 eV
# Max Force Component    =     0.1509 eV/Ang
# Geometry optimization step : 22
# Total Energy           =-16526.6170 eV
# Max Force Component    =     0.3061 eV/Ang
# Geometry optimization step : 23
# Total Energy           =-16526.6237 eV
# Geometry optimization step : 24
# Total Energy           =-16526.6234 eV
# Max Force Component    =     0.1069 eV/Ang
# Geometry optimization step : 25
# Total Energy           =-16526.6239 eV
# Max Force Component    =    -0.0614 eV/Ang
# Geometry optimization step : 26
# Total Energy           =-16526.6218 eV
# Max Force Component    =    -0.2947 eV/Ang

7

General Questions and Answers / Geometry optimization

« on: May 24, 2010, 03:07 »

hi, i used Quasi Newton method to optimize a supercll with vacuum. however, it can not converge by using the default parameters, the error is "Quasi Newton minimization unable to reach minimum with given force tolerance". note that the max_steps have not reached. which parameters shoul i adjust? may i decrease the trust radius?

8

General Questions and Answers / Re: The convergence problem for transmission coefficient

« on: May 11, 2010, 13:33 »

well, i'll try to know the T(E) as a function of k~~
thank you for suggestions.

9

General Questions and Answers / Re: The convergence problem for transmission coefficient

« on: May 11, 2010, 11:46 »

er, the system is used to perform the magnetoresistance, so it is isolating.
but the transmission coefficients at fermi level under zero bias is important, like the case of Fe-Mgo-Fe.

10

General Questions and Answers / The convergence problem for transmission coefficient

« on: May 11, 2010, 04:54 »

Hi，everyone，
i calculated transmissions for some 2D systems, like films. when i analyze the transmission coefficients, i test the brillouinZoneIntegrationParameters.
i use (k,1) to see if the coefficients can be converged. but the results are sad. It cannot converge even i use the kpoints of 1001*1. Any of you suggestions may beneficial to my work. Thank you~

the K points i used and the transmission coefficients for Spin.up and Spin.down are shown as follow:
101*1
1.97879210473e-009
2.08923627732e-009
201*1
0.00126760183962
4.66436520168e-005
301*1
2.06801372358e-009
2.13540912195e-009
401*1
1.97401526529e-008
1.24798756185e-008
501*1
0.000508560424445
1.87149713437e-005
601*1
6.24585146946e-009
5.30735471099e-009
701*1
7.91718763235e-007
2.2652668481e-008
801*1
0.000318090916723
1.17079069242e-005
901*1
1.75635227975e-008
8.55466170945e-009
1001*1
8.67660115626e-008
3.22559497865e-008
1101*1
0.000231421576928
8.52033531058e-006

11

General Questions and Answers / Re: Convergence problem at high bias voltage

« on: May 10, 2010, 15:35 »

Hi, Nordland,
you mentioned that as for the pure metallic system, a better way to make it convergence is to make the system longer. Should i make the electrode longer or scattering region longer? And what is the effect of those two way on the convergence?

12

General Questions and Answers / how to calculate the eigenstates for a band

« on: January 22, 2010, 05:41 »

in atk , the eigenstates for a band could be calculated in a specified kponit. but how can i calculate the band in whole kponits.
or, how to add all the eigenstates for many kpoints together?

13

General Questions and Answers / questions for mulliken population

« on: December 12, 2009, 10:09 »

Can the mulliken population projected to the orbital? namely, can atk output the mulliken population for s, px, py, pz……respectively?

14

General Questions and Answers / the transmission cannot match the DOS

« on: August 30, 2009, 15:09 »

hi , Norland and all
i have got the transmission and the relative DOS for some systems, as shown in the attachment.
i can see the enhancement of DOS, but it did not match in the transmission.
i did not know if i made some mistakes in my calculation, or that's all right but i should give some other reasons to explain it.

15

General Questions and Answers / Re: Questions about the Hamiltonian

« on: August 15, 2009, 09:46 »

hi, Nordland,
I have awared that the dimension of the Hamiltonion is depend on different basis set
but in my way, all of thouse are unregular.