Messages

1

General Questions and Answers / Is this result credible

« on: November 9, 2012, 08:20 »

hello, everyone, when i perform a two-probe calculation by using ATK-2008.10, at a bias of 1.0V, the self-consistent iteration is as follows:

# sc 117 : q =  668.98978 e  dRho =  3.4729E+00
# sc 118 : q =  669.07139 e  dRho =  1.5897E+00
# sc 119 : q =  669.13534 e  dRho =  3.4033E+00
# sc 120 : q =  669.13711 e  dRho =  7.8281E-03
# sc 121 : q =  669.14372 e  Etot = -7024.61255 Ry  dRho =  1.2260E-01
# sc 122 : q =  669.14696 e  Etot = -7024.61370 Ry  dRho =  8.1020E-01  dEtot = -1.1522E-03 Ry
# sc 123 : q =  669.15218 e  Etot = -7024.59930 Ry  dRho =  4.0362E-01  dEtot =  1.4403E-02 Ry
# sc 124 : q =  669.14950 e  Etot = -7024.59930 Ry  dRho =  2.9539E-01  dEtot = -3.6075E-06 Ry
1.0      8.41e-08

this current has a 2~3 orders of magnitude difference from those of bias on both sides,

voltage(V)     current(A)
0.8      1.03E-5
1.0      8.41E-8
1.2      6.73E-6

is this result credible? thanks very much!

2

General Questions and Answers / direction of the gate

« on: March 2, 2011, 13:16 »

hello everyone, in 'gated twoprobe method', what is the direction of the applied gate voltage. in the manual, it says that 'the electrostatic effect of the gate electrode is simulated by simply shifting the scattering region part of the Hamiltonian with the gate voltage (converted into an electrostatic potential energy).' does it mean that the gate electric field is perpendicular to the molecular plane ?

3

General Questions and Answers / Accuracy of the calculated results

« on: February 17, 2011, 02:36 »

hello everyone. as we know that the coherent electron transport scheme is only applicable to the low-voltage regime (usually not beyond 1 V). phonon-assisted electron transport may be dominant at high voltages. so how can ensure our results in range (-3v, 3v) obtained by using atk? thank you very much.

4

Installation and License Questions / Job Running Error

« on: January 12, 2011, 12:31 »

hello, everyone.
an running error occured when i drop a script into the "job manager" of vnl 10.8.2. anyone can help me？

5

General Questions and Answers / Re: about building a molecular junction

« on: January 12, 2011, 11:13 »

I did one thing differently compared to you, didn't realize it was critical. I first rotated your molecule 90 degrees about the Y axis (in the Builder). The idea with this was to have the two S atoms along Z already to begin with.

Thank you very much !

6

General Questions and Answers / Re: about building a molecular junction

« on: January 12, 2011, 03:08 »

The key is to set the "Bonding angle" to 30 degrees. Also note that the top layer is 0.

i have tried that, but it still didnot work.

7

General Questions and Answers / Re: about building a molecular junction

« on: January 11, 2011, 12:46 »

Can you attach the molecule (only!) as a Python file, then I can try.

Thank you !

8

General Questions and Answers / Re: about building a molecular junction

« on: January 11, 2011, 12:18 »

The right-hand alignment layer should be equivalent to the left. Since the structure is not mirror symmetric, this means it's not necessarily the same layer number when counted from the surface. Try setting the right alignment layer to 3!

no matter setting the right alignment layer to any number, it does not make any influence on the orientation of the molecule.

9

General Questions and Answers / Re: about building a molecular junction

« on: January 11, 2011, 11:43 »

Use the Custom builder "Molecular junction" and make sure to align the right-hand sulphur atom to the same surface layer as the left one.

i just did it in "molecular junction" tool, 8 and 10 atoms are sulfur atoms, and the alignment layer for left and right surface are both 2. But it still can't make the two S atoms align in z-axis.

10

General Questions and Answers / about building a molecular junction

« on: January 11, 2011, 08:45 »

hello, everyone. i'm new to vnl 10.8. when i'm building a molecular junction, my goal molecule is like pic.1.

but in vnl 10.8 (pic.2) i can't make the two sulfur atoms align with z-axis. how can i do that? also how to change the number of layers in surfaces and electrode? much thanks.

11

General Questions and Answers / About Optimization

« on: November 16, 2010, 04:17 »

hello everyone. i have one question, when i use 'gated two probe method' to calculate transport properties, i first optimize the two probe systerm without gating, and then apply the gate voltage and two probe bias to calculate IV curve, is this ok? or does it necessary to optimize the systerm again after applying the gate voltage? thank you.

12

Scripts, Tutorials and Applications / Re: how to construction multilayer's graphene (1-5layers) based on a gold electrode

« on: December 21, 2009, 02:52 »

My opinion is that you can change PAC = False , and construct numbers of scripts like this (you wanted), then drop them into 'Atomic Manipulator' as molecules and tune each relative position.