Messages

31

General Questions and Answers / Re: construct Au electrode with 2 × 2 layers in x and y directions

« on: January 13, 2014, 12:59 »

     Thank you for your guide.
   You mean in the Builder, I should add a Gold structure(FCC) from the Database. Then Press the "send to" button in the lower righter corner of Builder and select the Script Generator.

    In the Script Generator, add a New Calculator and a Optimize Geometry block to optimize the Gold structure.
    In the New Calculater, the number of K-points is 3*3*50.
    In the Optimize Geometry block, I remove the tick from the cell constraint in X,Y and Z direction, and the stress tolerance to 0.001eV/Å.
    Then the script is send to the Job Manager.
 
    I have done it as above. But the results of the structure show that there is no change at all.
   And what should I do next? Repeat the optimized Gold structure in X,Y and Z direction? I am not sure. The attached picture shows the electrodes I want.
  

32

General Questions and Answers / construct Au electrode with 2 × 2 layers in x and y directions

« on: January 12, 2014, 12:45 »

Dear friends,
   I am trying to construct Au electrodes with  2 × 2 layers in x and y directions and eight slabs in Z direction. As i don`t know the experimental parameter of Au electrode, so i have tried a lot of times to optimize the structure of Au electrode. No matter what i did, the results were not what i want. So if you could give me some directions or help. I would very appreciate it.

33

General Questions and Answers / Re: Fcc NaCl including 8 atoms

« on: January 8, 2014, 06:51 »

Thank you, Shinji and  Umberto! That`s really help me a lot! This problem,you know, really makes me confused for several days! I feel so lucky to get both of your help! Well, think you, again! 

34

General Questions and Answers / Re: Fcc NaCl including 8 atoms

« on: January 7, 2014, 07:36 »

Dear my friend,

   Thank you for your reply! The following is my input file.


# Set up lattice
lattice = FaceCenteredCubic(5.64056*Angstrom)

# Define elements
elements = [Sodium, Sodium, Sodium, Sodium, Chlorine, Chlorine, Chlorine, Chlorine]

# Define coordinates
fractional_coordinates = [[ 0. , 0. , 0. ],
                          [ 0. , 0. , 1.0],
                          [ 0. , 1.0, 0. ],
                          [ 1.0, 0. , 0. ],
                          [ 0.5, 0.5, 0.5],
                          [ -0.5, 0.5, 0.5],
                          [ 0.5, -0.5, 0.5],
                          [ 0.5, 0.5, -0.5]]

# Set up configuration
bulk_configuration = BulkConfiguration(
    bravais_lattice=lattice,
    elements=elements,
    fractional_coordinates=fractional_coordinates
    )

Looking forward to your reply!
Thanks again!

35

General Questions and Answers / Fcc NaCl including 8 atoms

« on: January 6, 2014, 03:23 »

when i use the ATK to construct a Fcc NaCl including 8 atoms, there is always existing the same mistake reminder:

{Back Engine Exception : Diagonalization error, overlap matrix not positive definite. This may be caused by atoms that are too close to each other or situated in equivalent positions, or (in the Extended Huckel model) a too low value of interaction_max_range
** Location of Exception : mathutils.cpp:687
This application has requested the Runtime to terminate it in an unusual way.
Please contact the application's support team for more information.}

So, i don`t know how to do with it. Please help me.
Thanks!