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1

General Questions and Answers / Re: Is it reasonable for this statement

« on: April 5, 2012, 05:22 »

Thanks!

2

General Questions and Answers / Is it reasonable for this statement

« on: April 3, 2012, 12:29 »

If I execute molecular simulation according following script. We describe the method as ‘we execute an dynamics simulation on the system at room temperature (T=300 K) with a time step of 1 fs.’ Is it reasonable for this statement? If it is not reasonable. How should I describe this method in right way.

initial_velocity = MaxwellBoltzmannDistribution(
   temperature=300.0*Kelvin
   )
method = VelocityVerlet(
   time_step=1.0*femtoSecond,
   initial_velocity=initial_velocity
   )

3

General Questions and Answers / Re: spin charge densities and partial charge densities

« on: January 10, 2012, 15:31 »

Thanks! In ATK, is it possible to get real space spin charge densities in a 1D nanoribbon directly? If I calculate ‘electron density’ using ATK, is it real space spin charge densities?

4

General Questions and Answers / spin charge densities and partial charge densities

« on: January 9, 2012, 14:44 »

How can I get the partial charge densities in the Fig. 4 of reference (J. Phys. Chem. C 2011, 115, 16644–16651) by using ATK. If I calculate ‘eigenstates’ of Gamma point using ATK , is it partial charge densities?

Moreover,in ATK, how can I get real space spin charge densities and partial charge densities at Fermi level for antiferromagnetic 4-ZGNR?

5

General Questions and Answers / Re: the difference of spin up and spin up current

« on: June 23, 2011, 03:28 »

I am sorry that it is a typo. The bias is 0.1 V. If I will publish this result in Scientific journal，what can I do with this situation?
For the second question，the threshold voltage should be 0.1 V when the band gap is 0.1 V. In my modle, the system is quasi-one-dimensional structure. Therefore, in ATK 2008.10, I only change the K point into 1, 1, 100 in the two probe system. Other parameters are the default. Should I change some parameters? However, when the band gap is much lager than 0.1 eV, similar situation can not be found. The I-V curve can reprensent the semiconductor performance of the system.

6

General Questions and Answers / Re: the difference of spin up and spin up current

« on: June 22, 2011, 09:11 »

In previos calculation, we also meet similar question. For example, when I calculate a two probe system, the left and right electrtodes are same semiconductor electrodes. The band gap is 0.1 eV. Theoretically, the threshold voltage should be 0.2 V. However, when the bias is set to 0.01 V, the current still can reach 1.19036166221e-07 A. It seems that I-V current cannot represent the semiconductor performance of the system. In calculation, the basis set is DZP.

7

General Questions and Answers / the difference of spin up and spin up current

« on: June 22, 2011, 08:51 »

Recently, I calculate a spin-polarized system. When the bias is 1.0 V, the spin up and spin down current is 5.0551131779e-12 and 5.41429995254e-08, respectively. However, the simultaneously
calculated transmission coefficient for spin up and spin down is zero whthin bias window. Why?
# Energy (eV) Spin-Up Coefficient Spin-Down Coefficient
-1.00 0.0001 0.0007
-0.98 0.0001 0.0002
-0.96 0.0000 0.0001
-0.94 0.0000 0.0001
-0.92 0.0000 0.0000
-0.90 0.0000 0.0000
-0.88 0.0000 0.0000
-0.86 0.0000 0.0000
-0.84 0.0000 0.0000
-0.82 0.0000 0.0000
-0.80 0.0000 0.0000
-0.78 0.0000 0.0000
-0.76 0.0000 0.0000
-0.74 0.0000 0.0000
-0.72 0.0000 0.0000
-0.70 0.0000 0.0000
-0.68 0.0000 0.0000
-0.66 0.0000 0.0000
-0.64 0.0000 0.0000
-0.62 0.0000 0.0000
-0.60 0.0000 0.0000
-0.58 0.0000 0.0000
-0.56 0.0000 0.0000
-0.54 0.0000 0.0000
-0.52 0.0000 0.0000
-0.50 0.0000 0.0000
-0.48 0.0000 0.0000
-0.46 0.0000 0.0000
-0.44 0.0000 0.0000
-0.42 0.0000 0.0000
-0.40 0.0000 0.0000
-0.38 0.0426 0.0000
-0.36 0.1117 0.0000
-0.34 0.1728 0.0000
-0.32 0.2361 0.0000
-0.30 0.3033 0.0000
-0.28 0.3752 0.0000
-0.26 0.4511 0.0000
-0.24 0.5724 0.0000
-0.22 0.6425 0.0000
-0.20 0.0010 0.0000
-0.18 0.0000 0.0000
-0.16 0.0000 0.0000
-0.14 0.0000 0.0000
-0.12 0.0000 0.0000
-0.10 0.0000 0.0000
-0.08 0.0000 0.0000
-0.06 0.0000 0.0000
-0.04 0.0000 0.0000
-0.02 0.0000 0.0000
0.00 0.0000 0.0000
0.02 0.0000 0.0000
0.04 0.0000 0.0000
0.06 0.0000 0.0000
0.08 0.0000 0.0000
0.10 0.0000 0.0000
0.12 0.0000 0.7371
0.14 0.0000 0.5006
0.16 0.0000 0.3802
0.18 0.0000 0.2697
0.20 0.0000 0.1390
0.22 0.0000 0.0000
0.24 0.0000 0.0000
0.26 0.0000 0.0000
0.28 0.0000 0.0000
0.30 0.0000 0.0000
0.32 0.0000 0.0000
0.34 0.0000 0.0000
0.36 0.0000 0.0000
0.38 0.0000 0.0000
0.40 0.0000 0.0000
0.42 0.0000 0.0000
0.44 0.0000 0.0000
0.46 0.0000 0.0000
0.48 0.0000 0.0000
0.50 0.0000 0.0000
0.52 0.0000 0.0000
0.54 0.0000 0.0000
0.56 0.0000 0.0000
0.58 0.0000 0.0000
0.60 0.0000 0.0000
0.62 0.0000 0.0000
0.64 0.0000 0.0000
0.66 0.0000 0.0000
0.68 0.0000 0.0000
0.70 0.0000 0.0000
0.72 0.0000 0.0000
0.74 0.0000 0.0000
0.76 0.0000 0.0000
0.78 0.0000 0.0000
0.80 0.0001 0.0000
0.82 0.0001 0.0000
0.84 0.0001 0.0001
0.86 0.0003 0.0001
0.88 0.6576 0.0001
0.90 0.8300 0.0002
0.92 0.8966 0.0047
0.94 0.9314 0.8496
0.96 0.9521 0.9304
0.98 0.9653 0.9609
1.00 0.9742 0.9756

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General Questions and Answers / Re: Is it reasonable for this statement

General Questions and Answers / Is it reasonable for this statement

General Questions and Answers / Re: spin charge densities and partial charge densities

General Questions and Answers / spin charge densities and partial charge densities

General Questions and Answers / Re: the difference of spin up and spin up current

General Questions and Answers / Re: the difference of spin up and spin up current

General Questions and Answers / the difference of spin up and spin up current