Author Topic: "Spatial Sizes," two probe systems and super cell vectors  (Read 3995 times)

0 Members and 1 Guest are viewing this topic.

Offline BandTheory

  • Heavy QuantumATK user
  • ***
  • Posts: 26
  • Reputation: 0
    • View Profile
Hello,

Today I received the following error:

NLValueError: The resulting electrode cells for the electrodes have different spatial size in the A direction

So I'm guessing this has something to do with the super cell vectors.  A guess only.  Something about propagating the system about with the super cell vectors to do some Fourier business ?

I'm working with heterogeneous electrodes by the way, a (4,4) CNT on one side and a copper surface on the other.  If that were not the case I would just make both sets of super cell vectors the same, but since that is the case I am not sure how to change the vectors, assuming that is the issue.

Any help would be much appreciated,

BT

Offline Anders Blom

  • QuantumATK Staff
  • Supreme QuantumATK Wizard
  • *****
  • Posts: 5576
  • Country: dk
  • Reputation: 96
    • View Profile
    • QuantumATK at Synopsys
Re: "Spatial Sizes," two probe systems and super cell vectors
« Reply #1 on: October 30, 2009, 21:53 »
The supercell vectors in the two directions perpendicular to the transport direction must be identical for left and right electrode, this is a fundamental assumption in these calculations.

However, in your system this is trivial to achieve; just make the proper unit cell to describe the Cu side, and then add enough vacuum to the CNT side to make it equal.