How do I solve SCF convergence issues in TranSIESTA?

TranSIESTA convergence is not guaranteed, so a lot of trial and error is often required. Please find below some general tips that may help to improve convergence,

  • Sometimes a particular bias is difficult to converge due to a state just at the chemical potentials. It may help to increase the bias by a little amount (say 0.05 eV).
  • Play with convergence parameters for the bias-points that are causing you problems. It is the only way to solve the problems.
  • When starting/restarting bias calculations with tranSIESTA, please copy the TSDE file from the closest bias to significantly speed up convergence.
  • Increasing the size of the electrodes (along the transport direction) may only help if they are too small, increasing in SR should always help.