Topics

1

General Questions and Answers / potential in bilayer system

« on: April 1, 2011, 12:05 »

sir,
   in the case of bilayer system with out applying any potential conduction band comes above zero and valance band come below zero.while applying positive voltage both valance band and conduction band come below zero.while applying negative  voltage both valance band and conduction band come above zero.

but in my simulation both positive and negative voltage conduction band comes above zero and valance band come below zero.i didnt get valance band and conduction band shift.

with this i attached two band structure diagram.

2

General Questions and Answers / construction details of Graphene on hexagonal boron nitride bilayer system

« on: February 17, 2011, 07:11 »

sir,
    i am trying to obtain the results  by performing density functional calculations for
bilayer graphene/h-BN system in tetrahedron method using ATK.I took Z=16 A,X=2.456 A.
But they were used the same thing using QE.In QE z dirction is fixed but in the case of ATK x direction is fixed.If i used the same Z and X direction value in ATK i cant able to fix 3 layers.could you help me how to construct 3 layers.i constructed the same thing using ATK but i changed Z&X direction values.but i didnt get the same curve.

3

General Questions and Answers / pseudopotential problem

« on: February 8, 2011, 07:58 »

sir,
     while executing the program i got the pseudopotential error.i try to reproduce one paper result they are using Ultrasoft pseudopotential.The pseudo was generated with Non-Relativistic Calculation.But in the case of ATK Norm-conserving pseudopotential was used.That pseudopotential was generated using Scalar-Relativistic Calculation.Could you tell me the difference between these two method .

4

General Questions and Answers / pseudopotential

« on: February 8, 2011, 05:55 »

sir,
    while executing the program(GNR) i got pseudopotential error.could you give the information about pseudopotential of carbon in ATK,VASP.

5

General Questions and Answers / Radius of the capped end of Nanotube

« on: January 28, 2011, 10:30 »

for nanotubes if the configuration(n,m) is known it is possible to calculate the radius of the nanotube from it.But if the ends of a give (n,m) is capped, How to calculate the radii of the capped end of the tube.

Because some papers report different configurations for the capped structure.

Whether the radii of the capped end nanotube is related to the (n,m) value of the nanotube, if yes how

6

General Questions and Answers / Stress effect

« on: January 10, 2011, 11:36 »

sir,
     with this i attached one file from Anisotropy of the Stone-Wales Defect and Warping of Graphene Nano-ribbons: A First-principles Analysis .i need to introduce the stress in GNR.i dont know how to introduce Stress in GNR using ATK.In that paper they used Quantumespresso software to get the result.


could you help me how to introduce Stress in GNR using ATK.