[Pw_forum] Units in dynamical matrix files

[Serge Nakhmanson]

I had to ponder this question some time ago.

I think the difference here is the same as
between Ry and Ha energy units, so that in
the "convention" that QE uses an extra 1/2
proliferates into the mass units as well.

But this is my guess, which may not be the
ultimate truth. Actually, considering how
many times I get my butt handed back to me
in this forum, I could be totally wrong
about it.

Cheers,

S.

Cristian Degli Esposti Boschi wrote:
> 
> Am I right? Why the 1/2 factor?
> 
> And what are the typical units used for force constants?


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  Serge M. Nakhmanson               phone: (630) 252-5205
  Assistant Scientist                 fax: (630) 252-4798
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  Argonne National Laboratory
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