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1

General Questions and Answers / Re: how to construct graphene electrodes with different width

« on: September 20, 2009, 06:31 »

I see. Thanks a lot

2

General Questions and Answers / how to construct graphene electrodes with different width

« on: September 19, 2009, 16:35 »

Hello, everyone.
I want to constuct zigzag graphene electrodes with differents width, left width=8, right width=12.
Because the width of the graphene nano ribbon in central region is different, left width=8, right width=12.

The steps are as follows
1） I constructed identical electrodes with width=12
2） Then I edited the script file. I wrote left and right eletrodes separately, including the electrode_cell, elements, coordinates
    I want to delete 4 carbon atoms of the left electrodes at two ends of X axis.
Here, one problem occurred. Both the left electrode and right electrode shift down along X axis.
Although I did not edit the right electrode.
Moreover, the electrodes can not match the surface atoms.

I do not understand. Why? How to construct this type of electrodes?

Thanks a lot.

The following is part of the script file.

left_electrode_elements = [Carbon,   Carbon,   Carbon,   Carbon,   
                      Carbon,   Carbon,   Carbon,   Carbon,   
                      Carbon,   Carbon,   Carbon, 
                      Hydrogen]
left_electrode_coordinates = [[ 16.81142998,  15.        ,   1.84575129],
                         ..........

                         [ 28.56888008,  15.        ,   0.61525041]]*Angstrom
         
right_electrode_elements = [Carbon,   Carbon,   Carbon,   Carbon,   
                      Carbon,   Carbon,   Carbon,   Carbon,   
                      Carbon,   Carbon,   Carbon,   Carbon,   
                      Hydrogen, Hydrogen]
                     
right_electrode_coordinates = [[ 16.10099983,  15.        ,   0.61525041],
                        .................
                         [ 28.56888008,  15.        ,   0.61525041]]*Angstrom

left_electrode_cell = [[ 43.56888   ,   0.        ,   0.        ],
                  [  0.        , 43.56888   ,   0.        ],
                  [  0.        ,   0.        ,   2.46100171]]*Angstrom
right_electrode_cell = [[ 43.56888   ,   0.        ,   0.        ],
                  [  0.        ,  43.56888   ,   0.        ],
                  [  0.        ,   0.        ,   2.46100171]]*Angstrom

# Set up electrodes
left_electrode_configuration = PeriodicAtomConfiguration(
    left_electrode_cell,
    left_electrode_elements,
    left_electrode_coordinates
    )
   
right_electrode_configuration = PeriodicAtomConfiguration(
    right_electrode_cell,
    right_electrode_elements,
    right_electrode_coordinates
    )
   
# Set up two-probe configuration
twoprobe_configuration = TwoProbeConfiguration(
    (left_electrode_configuration,right_electrode_configuration),
    scattering_elements,
    scattering_coordinates,
    electrode_repetitions=[[1,1],[1,1]],
    equivalent_atoms=([0,0],[1,130])