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QuantumATK => General Questions and Answers => Topic started by: Poornimadevi on December 15, 2023, 06:43

Title: IV points convergence problem
Post by: Poornimadevi on December 15, 2023, 06:43

Hello all,
 For the past 4 months, I have been trying to calculate the IV characteristics of the doped WS2 material.
1. With the tutorial's guidance, I first transformed hexagonal WS2 into a unit cell. Then I calculated the IV. But the problem is all the points are not converging.
2. Then I tried various  modifications like,
   * Increase the length of the device's central region
   * Increase the length of the electrodes.
   * boundary conditions (periodic in AxB, Dirichlet in C)
   * increasing the k-points (1x1x150, 1x1x200, 4x4x150, 2x3x150)
   * for initial density use equivalent bulk
   * Poisson solver (multigrid, conjugate gradient solver)
   * Increased the density mesh cut-off energy (40H, 125H)
But still, in IV the given points are not converged.

Title: Re: IV points convergence problem
Post by: AsifShah on December 19, 2023, 13:37

Hi,

Try changing parameters in iteration settings in LCAO device calculator or
Say suppose 0.1 is not converging use 0.11 or 0.15 instead.

Title: Re: IV points convergence problem
Post by: Poornimadevi on December 20, 2023, 07:46

Thanks for your suggestion. I will try and let you know:)