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Topics - yangzw1985

Pages: [1] 2 3
1
General Questions and Answers / Can ATK calculate I-V curves for a bulk
« on: January 18, 2010, 03:21 »
Hi, everyone!

As we know, ATK can calculate I-V curves for two probe model. Now, I want to know: can ATK calculate I-V curves for a bulk? If yes, how to achieve it?

I have built a model in atomic manipulator, and saved it as equivalent bulk, and then dragged it to the nanolanguage scripter. But, in the analysis menu, current does not include in the available quantities.

Thanks!

2
General Questions and Answers / Can anyone give me some suggestions?
« on: January 10, 2010, 14:50 »
Hi everyone,

Now, I want to perform some calculations for a two probe model, and the insert strccture in the central region is a C wire. As we all know, the C wire should be saturated by Hydrogen or others.

when I read some papers, I found that the C wire surface was fully saturated by H atoms, but the cross section was not been saturated. Just like the attached wire 1 in picture. But when we saturate the C wire, it should be like wire 2 in picture.

I want to know, if we want to performed the calculation, should the two probe model be metal-H-C-H-metal or metal-C-metal? In other words, should we use the wire 1 or wire 2?

I was confused for a long time, why some of the H atoms was truncated in the cross section? Can anyone give me some suggestions?

Thanks!

3
General Questions and Answers / How was the band alignment been tackled in ATK/VNL calculation?
« on: December 28, 2009, 01:05 »
Hi, everyone.

When I read papers, I found that the alignment of the fermi level relative to the molecule's HOMO and LUMO in a two probe model is extremely sensitive to charger transfer and conductance.

For example, calculated transmission is strongly dependent on the offset between the  HOMO energy level and Fermi level for systems where hole transport dominates. if the Fermi energy lies far from the HOMO energy, the system will have a lower transmission than if the Fermi energy lies close to the HOMO.

Can anyone tell me how was the band alignment been tackled in ATK/VNL calculation for two probe systems?

Thanks!



4
General Questions and Answers / Can anyone tell me is the calculated results right or not?
« on: November 20, 2009, 13:43 »
As you can see, I have calculated the transmission apectra for a two probe model, first, the results like this:

# Electrode Voltages
# -----------------------------------------------------------------------------
Voltage at Electrode 0 = 0.50 V
Voltage at Electrode 1 = -0.50 V


334 Li     q =  1.59730 [ s:  0.686, py:  0.248, pz:  0.421, px:  0.243 ]
335 Li     q =  1.86994 [ s:  0.786, py:  0.273, pz:  0.544, px:  0.267 ]
#-------------------------------------------------------------------------------
# Total Charge =  597.71486
#-------------------------------------------------------------------------------
6.57893849447e-10 A
# -----------------------------------------------------------------------------
# Density Of States
# -----------------------------------------------------------------------------
# Energy (eV)   DOS (1/eV)
        -5.00       0.0018
        -4.97       0.0001
        -4.93       0.0000
         
        -2.53     579.6176
        -2.50    1154.2454
        -2.47    1102.2968
        -2.43     524.1090
     
        -0.27    2601.1999
        -0.23    2123.6188
        -0.20    2050.1497
        -0.17    2200.1483
        -0.13    2252.9818
        -0.10    2061.0337
        -0.07    2122.2064
        -0.03    2097.8951
        -0.00    2925.4176
         0.03    2584.9053
         0.07    2611.8116
         0.10    2361.7115
         0.13    2121.0169
         0.17    2150.3446
         0.20    2209.3314
         0.23    2133.2467
         0.27    2274.1125
         0.30    2285.1844
       
         4.50    3409.8495
         4.53    3378.1183
         4.57    3237.0752
         5.00    3740.9722
# -----------------------------------------------------------------------------
# Transmission Spectrum
# -----------------------------------------------------------------------------
# Energy (eV)   Coefficient
        -5.00        0.0000
        -4.97        0.0000
        -4.93        0.0000
       
        -3.40        0.0000
        -3.37        0.0000
        -3.33        0.0000
        -3.30        0.0000
       
        -2.60        0.0000
        -2.57        0.0000
        -2.53        0.0000
        -2.50        0.0000
        -2.47        0.0001
        -2.43        0.0000
        -2.40        0.0000
        -2.37        0.0000
        -2.33        0.0001
        -2.30        0.0001
        -2.27        0.0001
        -2.23        0.0002
        -2.20        0.0002
        -2.17        0.0002
        -2.13        0.0004
        -2.10        0.0007
        -2.07        0.0009
        -2.03        0.0007
        -2.00        0.0004
        -1.97        0.0003
        -1.93        0.0002
        -1.90        0.0001
        -1.87        0.0001
        -1.83        0.0001
        -1.80        0.0001
        -1.77        0.0001
        -1.73        0.0001
        -1.70        0.0001
        -1.67        0.0001
        -1.63        0.0000
        -1.60        0.0000
        -1.57        0.0000
        -1.53        0.0000
        -1.50        0.0000
        -1.47        0.0000
        -1.43        0.0000
        -1.40        0.0000
        -1.37        0.0000
        -1.33        0.0000
        -1.30        0.0000
        -1.27        0.0000
        -1.23        0.0000
        -1.20        0.0000
        -1.17        0.0000
        -1.13        0.0000
        -1.10        0.0000
        -1.07        0.0000
        -1.03        0.0000
        -1.00        0.0000
        -0.97        0.0000
        -0.93        0.0000
        -0.90        0.0000
        -0.87        0.0000
        -0.83        0.0000
        -0.80        0.0000
        -0.77        0.0000
        -0.73        0.0000
        -0.70        0.0000
        -0.67        0.0000
        -0.63        0.0000
        -0.60        0.0000
        -0.57        0.0000
        -0.53        0.0000
        -0.50        0.0000
        -0.47        0.0000
        -0.43        0.0000
        -0.40        0.0000
        -0.37        0.0000
        -0.33        0.0000
        -0.30        0.0000
        -0.27        0.0000
        -0.23        0.0000
        -0.20        0.0000
        -0.17        0.0000
        -0.13        0.0000
        -0.10        0.0000
        -0.07        0.0000
        -0.03        0.0000
        -0.00        0.0000
         0.03        0.0000
         0.07        0.0000
         0.10        0.0000
         0.13        0.0000
         0.17        0.0000
         0.20        0.0000
         0.23        0.0000
         0.27        0.0000
         0.30        0.0000
         0.33        0.0000
         0.37        0.0000
         0.40        0.0000
         0.43        0.0000
         0.47        0.0000
         0.50        0.0000
         0.53        0.0000
         0.57        0.0000
         0.60        0.0000
         0.63        0.0000
         0.67        0.0000
         0.70        0.0000
         0.73        0.0000
         0.77        0.0000
         0.80        0.0000
         0.83        0.0000
         0.87        0.0000
         0.90        0.0000
         0.93        0.0000
         0.97        0.0000
         1.00        0.0000
         1.03        0.0000
         1.07        0.0000
         1.10        0.0000
         1.13        0.0000
         1.17        0.0000
         1.20        0.0000
         1.23        0.0000
         1.27        0.0000
         1.30        0.0000
         1.33        0.0000
         1.37        0.0000
         1.40        0.0000
         1.43        0.0000
         1.47        0.0000
         1.50        0.0000
         1.53        0.0000
         1.57        0.0000
         1.60        0.0000
         1.63        0.0000
         1.67        0.0000
         1.70        0.0000
         1.73        0.0000
         1.77        0.0000
         1.80        0.0000
         1.83        0.0000
         1.87        0.0001
         1.90        0.0002
         1.93        0.0001
         1.97        0.0001
         2.00        0.0001
         2.03        0.0002
         2.07        0.0001
         2.10        0.0001
         2.13        0.0001
         2.17        0.0001
         2.20        0.0000
         2.23        0.0000
         2.27        0.0001
         2.30        0.0001
         2.33        0.0001
         2.37        0.0001
         2.40        0.0001
         2.43        0.0001
         2.47        0.0001
         2.50        0.0002
         2.53        0.0002
         2.57        0.0001
         2.60        0.0001
         2.63        0.0001
         2.67        0.0001
         2.70        0.0001
         2.73        0.0007
         2.77        0.0002
         2.80        0.0004
         2.83        0.0005
         2.87        0.0005
         2.90        0.0009
         2.93        0.0012
         2.97        0.0024
         3.00        0.0003
         3.03        0.0008
         3.07        0.0005
         3.10        0.0003
         3.13        0.0013
         3.17        0.0009
         3.20        0.0017
         3.23        0.0008
         3.27        0.0015
         3.30        0.0015
         3.33        0.0019
         3.37        0.0007
         3.40        0.0016
         3.43        0.0011
         3.47        0.0012
         3.50        0.0021
         3.53        0.0023
         3.57        0.0024
         3.60        0.0040
         3.63        0.0060
         3.67        0.0086
         3.70        0.0146
         3.73        0.0142
         3.77        0.0202
         3.80        0.0378
         3.83        0.0399
         3.87        0.0527
         3.90        0.0736
         3.93        0.0904
         3.97        0.1059
         4.00        0.1914
         4.03        0.2494
         4.07        0.4870
         4.10        0.7265
         4.13        0.7654
         4.17        0.6731
         4.20        0.5017
         4.23        0.4464
         4.27        0.4008
         4.30        0.3720
         4.33        0.3907
         4.37        0.4191
         4.40        0.4726
         4.43        0.5987
         4.47        0.8329
         4.50        1.0066
         4.53        1.0108
         4.57        0.8232
         4.60        0.7792
         4.63        0.8757
         4.67        1.2161
         4.70        1.3687
         4.73        1.3299
         4.77        1.4847
         4.80        1.6210
         4.83        1.4962
         4.87        1.5924
         4.90        1.7717
         4.93        1.5783
         4.97        1.6270
         5.00        1.8702
Terminated Normally
Run finished at  Mon Aug 11 23:19:57 2008!

5
General Questions and Answers / Projected Hamiltonian Energy Spectrum
« on: October 29, 2009, 09:36 »
Hi, everyone!

Now, I have performed a Projected Hamiltonian Energy Spectrum calculation on my model, and it just projected in molecule atoms. And it should be noted that it may not a molecule, it is a wire. Followed is the results.

 Total Charge =  615.86720
#-------------------------------------------------------------------------------
# -----------------------------------------------------------------------------
# Energy Spectrum
# -----------------------------------------------------------------------------
# Energy (eV)
       -20.10
       -19.67
       -19.07
       -18.78
            -17.29
       -17.28
       -17.26
       -16.75
          -15.81
       -15.58
       -15.50
       -15.34
       -15.32
       -15.06
       -15.03
           -13.99
       -13.98
       -13.94
       -13.89
       -13.73
       -13.48
             -8.93
        -8.79
        -8.75
        -8.75
        -8.60
        -8.59
            -7.43
        -7.40
        -7.36
        -7.35
        -7.34
        -7.34
        -7.19
             -5.03
        -5.03
        -4.96
        -4.91
             -4.64
      -2.95
        -2.88
        -2.85
        -2.76
        -2.62
        -2.56
        -2.43
        -1.44
        -1.27
        -0.41
         4.14
         4.43
         4.46
         4.59
         4.82
         4.97
         5.03
         5.04
             9.27
         9.28
         9.34
         9.34
         9.39
         9.41
            19.12
        19.20
        19.20
        19.29
        19.31
            39.59
        39.66
        39.68
        39.83
          66.56
        66.72
        66.73
        66.80
        66.89
            83.25
        83.45
        83.71
        83.86
Terminated Normally
Run finished at  Tue Jan 01 17:24:22 2008!

Attached is the exported Figure.

As we can see from the calculated results, it just contains the energy from -21.0--83.86.  Can anyone tell me how to draw this picture in origin?
Thanks!

6
General Questions and Answers / About PDOS
« on: October 27, 2009, 09:27 »
Hi, everyone!  As we can see, most of papers are talk about PDOS, but in VNL, we can just calculate DOS or/and LDOS for two probe model. Moreover, LDOS can be calculated for different energies. when I read the paper published in Nano Letters titled :Doping Molecular Wires, Vol9, No7,2559-2564,2009. I don't know how the PDOS shown in Figure 3.(a) and Figure 5 be calculated.  Can anyone tell me how to got the PDOS picture for a two probe model?

7
General Questions and Answers / Transmission spectra
« on: August 4, 2009, 14:25 »
Hi, everyone! Now, I have two questions to ask.

First,transmission spectra for two probe model, I want to know what is the really meant if there is no of peaks or magnitude of the transmission peaks in bais window.As far as I know, if there is no transmission peaks in bias window, meaning there are no electrons can through the scattering region.I want to know  explainations exactly.

Second,if I have calculated the transmission spectra for my two probe model, Is it possible to calculate the integrated transmission for different bias windows. If it is possible, how to carry it out?

Thanks in advance!

8
General Questions and Answers / how to get the table?
« on: June 19, 2009, 03:48 »
Hellow, everyone! I have been puzzling about the table 2 in Nano Lett. 2008 Nov;8(11):3662-7. Epub 2008 Oct 14.

I do not understand what is the real meaning of the first three Eigenchannels of the transmission? I want to know how to obtain the channel 1, channel 2 , channel 3 ,and the others?

In order to understand the table, I have try to calculate the transmission eigenstates and transmission eigenvalues of my two probe model, but the results are not like this.

In table 2, they also calculate the percentage probability of transmission, in my opinion, one channel should have a value, the wire should have lots of channels, so we can calculate the percentage. I don't know what I have said is right or not?

Can anyone tell me  how to distinguish the channel 1, channel 2 and channel 3.......? In other words, if I want to obtain the table, what should I do?

Thanks in advance!

9
General Questions and Answers / Wave functions of MPSH
« on: June 10, 2009, 04:45 »
Hellow, everyone! When I read the paper, I have see many picture of wave functions of MPSH states. If I have calculate the MPSH of a two probe model, I want to know how to got the picture. Can anyone tell me the methods? Thank you very much!

10
General Questions and Answers / When I want to save the two probe model, the problem occurs
« on: June 10, 2009, 04:30 »
Hi, everyone! I have build the two probe model, when I click SAVE/SAVE AS, the problem occurs. Attached is the warning picture. Can anyone help me to solve the problem? Thanks in advance!

11
General Questions and Answers / a picture
« on: June 1, 2009, 18:36 »
Hi,everyone!Attached is a picture, Can any one tell me how the dos can be display like this? In other words, HOW can I get the DOS picture OF VBM,CBM, FERMI LEVEL? Thanks!

12
General Questions and Answers / About MPSH
« on: May 31, 2009, 10:24 »
I have carried out the MPSH calculation of two probe model.But the HOMO-LUMO level are too narrow.what is the reason? Can anyone tell me how to recognize the results?Thanks in advance!

13
General Questions and Answers / Is there something wrong with the results?
« on: May 31, 2009, 10:05 »
Hi, everyone! I have calculated the transmission spectra and DOS of my two probe model.Attached is the calculated results.I don't understand why the coefficient is 0 when the EF is 0 eV.Is there something wrong?If not, what's the reason?Thanks!

14
General Questions and Answers / Transmittance!
« on: May 18, 2009, 07:27 »
Hi, everyone! I have carried out the transmission spectra calculation of my two probe model. It is a nanowire. when the wire is contaion 48 atoms or 72 atoms, the transmission spectra is different with the applied voltage of 0V. Under applied voltage (not zero), the current of 48 atoms is larger than 72 atoms.I want to know if the two probe model changed from metal to semi-conductor.Can any one help me to explain the difference?Thanks!

15
General Questions and Answers / Can anyone tell me the reasons?
« on: May 12, 2009, 05:17 »
Hi, I have calculated I-V characteristics of my two probe model. when the applied voltage of 0.4,0.8,1.2,1.6, the calculation finished normally with the sc is 70-100. But when the applied voltage of 0,0.2V, the calculation can not convergence, and log out window is still running with the sc is 300. why the low voltage calculation need so much time? can it finished normally? I really don't know the reason. Thanks!

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