[Pw_forum] symmetrized projection in atomic projected DOS
giannozz at nest.sns.it
Thu Feb 28 19:39:08 CET 2008
On Feb 28, 2008, at 5:01 , alan chen wrote:
> Dear PWSCF users,
> I have a question about the flag 'lsym' in the atomic
> projected DOS (projwfc.f90). The flag 'lsym' is set .true. by
> default. I ran it both with 'lsym' = .true. or .false. and found
> that if the Block state is nondegenerate, the decomposition into
> atomic orbitals is the same no matter whether 'lsym'=.true.
> or .false. However for those degenerate states, the coefficients
> are different. For example, if there are three degenerate Block
> states and 'lsym'=.true., the coefficients in the decomposition
> (i.e. modulous square of the overlap) are the same for these three
> states. If 'lsym' = false, the coefficients are different in the
> three states.
> So why are the results different if 'lsym' = true and false?
> And which one is correct?
> What is symmetrized projection?
- your third question should be the first one (and the only one)
- your second question doesn't make any sense: both are correct
- your first question doesn't make any sense either: they differ because
they are (slightly) different quantities
- the answer is contained in your observations
Disclaimer: I didn't write that part of the code
Paolo Giannozzi, Dept of Physics, University of Udine
via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222
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