Messages

1

General Questions and Answers / Re: Error about runtime_parameters

« on: November 30, 2009, 01:41 »

 Thanks very much for your help .I will have a try.

2

General Questions and Answers / Re: Error about runtime_parameters

« on: November 29, 2009, 11:45 »

Traceback (most recent call last):
  File "<string>", line 624, in ?
ATKError: inverse(DZMatrix const &) : Could not LU factorize!

3

General Questions and Answers / Re: Error about runtime_parameters

« on: November 29, 2009, 08:43 »

The problem is, as usual in these cases, the alignment atoms. It's clear that the system was built with VNL, but whether or not this indicates that the geometry produced by VNL is wrong or not is hard to say at this point... Perhaps you modified it by hand after it came out of the Atomic Manipulator?

Anyway, by changing the equivalent atoms from

Code

equivalent_atoms=([0,0],[2,220])

to

Code

equivalent_atoms=([0,0],[2,195])

I hope you will be able to run the simulation. It will require a lot of memory, and may be difficult to converge, but at least I think the error you obtained should not appear any more.

How did I find this out? It can be useful to know a bit more about how to troubleshoot a system like this...

What I did was to convert the two-probe to its equivalent bulk system. Not by using the functionality in VNL, in the Atomic Manipulator, but by using the NanoLanguage function, which is a method on the two-probe configuration object. Viewing this in VNL clearly showed that the system was misaligned.

After thinking a bit, and trying a lot of different things, what worked was 195 = 220-3*9+2, that is the alignment atom did not, somehow, account for the repetitions. (Here, 3 and 9 are the repetition factors, and 2 is the index for the electrode atoms, seen in the code above.)

Hello  Anders Blom
 When I calculate 2probe system ,I count the same question . Could you help me to inspect this script,thank you for your help.

4

General Questions and Answers / Optimize gemetry

« on: November 25, 2009, 14:13 »

Hello everyone
 I have calculated a two probe system and got the .nc file in 500 kelvin.
Now I want to get the gemetry in 300 kelvin. Do I have to calculate the system again .Whether can I optimize the gemetry from the previous results ?
 I have read the atk manu but it doesn't concern the tempreture,it just mean optimizing the gemetry more precisely,how deal with this situation.
  Thanks a lot.

5

Installation and License Questions / installation atk 2008.10

« on: November 25, 2009, 12:23 »

Hello
 
   When I install the atk 2008.10 ,there happened a problem

/home/wjtian/atk-linux/vnl-2008.10.0/bin/vnl_exec: error while loading shared libraries: libstdc++.so.6: wrong ELF class: ELFCLASS64

 What's wrong ? I am in trouble,please help me.
 

6

General Questions and Answers / Re: one question about the result of self-consistent calculation

« on: November 18, 2009, 15:09 »

Thank you for your answer.But C atom doesn't have d orbital.How to explain this phenomena?

7

General Questions and Answers / one question about the result of self-consistent calculation

« on: November 17, 2009, 10:56 »

hello everyone
  I calculate the spin system --A  two-probe system of the graphene nanoribbon .In the out file list some datas,for example

 0  C     q =  2.02095 [ s:  0.491, py:  0.474, pz:  0.507, px:  0.514, d(-2):  0.003, d(-1):  0.006, d( 0):  0.009, d( 1):  0.011, d( 2):  0.005 ]

 I want to know  the meaning about s,kx,ky,kz , d(-2)......
 If s,kx,ky,kz represent the spin of the orbit,what's the meaning of d() ?

8

General Questions and Answers / Re: how can we set the value of " initial_scaled_spin"

« on: November 16, 2009, 04:14 »

 hello
 When I calculate the two probe system with initial_scaled_spin,I have the same trouble .I want to calculate the ferromagnetism about the graphene nanoribbon,but I didn't know how add the spin to the two probe and scaled area.Do I need add the spin to the edge of the ribbon only? No spin in the center of the ribbon?Need I calculate total energy of many situations to centain the most steady states?
And I want to know whether it change the spin on every atoms when we have a self-consistent calculation.
 Thanks a lot.

9

General Questions and Answers / Can atk calculate one atom of local density of states

« on: November 13, 2009, 15:01 »

   Hello
  I want to calculate local density of states about one atom .But in atk manu, I feel it just calculate one point of the energy.And I can't understand how to fix the quantum numbers KA and KB .
   I just want to know whether it can calculate the local density states about  monatomic in atk .How to choose the quantum numbers?

  Thanks a lot.