Nicola Marzari wrote: > 6) this open up my favourite question - should B be spherical or > cylindrical in DFT ? I.e. should we look like for occupation 1 0 0 > for the 2p levels, or 1/3 1/3 1/3 ? > > 7) Last, but important - even using Gamma sampling, PWSCF finds > for your geometry 16 symmetry operations, and thus heavily > symmetrizes the system. That means that in 6) even 1 0 0 would > become spherical. I.e. the symmetrization has a similar effect > to temperature, in creating a charge density that is more symmetrical > /degenerate occupations than it could be. > > I would be *Very curious* to see what happens if you were to > put the dimer in a very random position, so the code misses most > of the symmetry operations, and also you specify no_sym, so no > symmetrization is performed. > nicola\ > > I agree with Nicola that this is very relevant and that symmetrization induces a degeneracy that could not be there in the best "broken symmetry" solution. This one can be achieved by 1) occupations='from_input' 2) nosym=.true. no smearing is required then.
stefano
