Topics

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 / 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.

6

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.