Determines the maximum number of iterations that the eigensolver will perform if the desired tolerance is not achieved. The default is 25 iterations for all eigensolvers except for rmdiis, which performs only 5 iterations. Increasing this value for rmdiis increases the convergence speed, at the cost of an increased memory footprint.
In the case of imaginary time propatation, this variable controls the number of iterations
for which the Hxc potential is frozen. Default is 1 for the imaginary time evolution.