Change stopping criteria for the SCF cycle
As agreed on the octopus developer's workshop in 2019, the default convergence criteria are updated:
Moreover, to make sure the convergence criteria are reached, the SCF loop is terminated only if the convergence criteria are fulfilled twice in subsequent iterations.
Change stopping criteria for the SCF cycle: tighter convergence thresholds; have to be fulfilled twice in a row
- I have checked that my code follows the Octopus coding standards
- I have added tests for all the new features added in this request.
Closes #166 (closed)