[Pw_forum] pwcond-problem with linear system

2009-07-22 Thread ambavale sagar
Dear all,
I am running a pwcond program for system made of Al electrodes and vaccum (> 10 
angstrom) in between. Even for such a large vaccum I get nonzero values (10e-1 
to 10e-4) of transmission coefficient (T) at higher energies (> 2 eV +Ef). for 
energies < 2 eV, T become almost zero. After 0.8 eV +Ef energy the program got 
terminated giving error:
 error # 5411
problems with the linear system. 
What might be a source of error in my case? Can I substract this contribution 
of leads from the T values I got for electrode-molecule-electrode system to get 
accurate T in case of molecule attached to electrodes?
The other question is little sidelined. Why Al is not used as electrode in most 
of the studies? In other words, what are the drawbacks of using Al as an 
electrode?

regards
Sagar Ambavale
PhD student
M.S. University of Baroda
India



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[Pw_forum] pwcond-problem with linear system

2009-07-22 Thread Manoj Srivastava
Dear Sagar, 
 The error 'Problems with the linear system' generally gets
removed if you change 'ecut2d' parameter, which is the 2D energy cutoff
and determines how many plane waves would you have in your calculation. I
am guessing that the other problem is also coming from energy convergence.
I suggest to check that.

-Manoj 

On Wed, 22 Jul 2009, ambavale sagar wrote:

> Dear all,
I am running a pwcond program for system made of Al electrodes and vaccum (> 10 
angstrom) in between. Even for such a large vaccum I get nonzero values (10e-1 
to 10e-4) of transmission coefficient (T) at higher energies (> 2 eV +Ef). for 
energies < 2 eV, T become almost zero. After 0.8 eV +Ef energy the program got 
terminated giving error: error # 5411
problems with the linear system. 
What might be a source of error in my case? Can I substract this contribution 
of leads from the T values I got for electrode-molecule-electrode system to get 
accurate T in case of molecule attached to electrodes?
The other question is little sidelined. Why Al is not used as electrode in most 
of the studies? In other words, what are the drawbacks of using Al as an 
electrode?

regards
Sagar Ambavale
PhD student
M.S. University of Baroda
India



  See the Webs breaking stories, chosen by people like you. Check out 
Yahoo! Buzz. http://in.buzz.yahoo.com/