Use of H for bands without executing a scf step
The computation of H outside the scf loop implemented in !48 (merged) opens an intriguing possibility: Imagine you have a DM from a previously converged calculation, and would like to compute a band structure. Previously you had to have at least one scf step to generate H from the DM, and then you had to diagonalize. Now, in principle, it should be possible to set:
#-------- to create H for bands without any diagonalization compute-forces F dm.use-save-dm T use-save-dm T MaxSCFIterations 0
and re-use the DM to compute the bands with the H generated before the (empty) scf loop.
The problem is that I cannot make it to work... I need to check further whether H is still changed somewhere along the way.