[Q-e-developers] Polar mode contributions to permittivity

[William Parker]

Dear developers,

I've added a subroutine to dynmat that calculates the zone-center polar mode contributions to the dielectric permittivity tensor following the method outlined by Craig Finnie and Karin Rabe in Phys. Rev. B 68, 184111.  I couldn't find this elsewhere in Q/E so I'm presuming no one else has done it.  

I was wondering if the SI values of vacuum permittivity and permeability are defined somewhere.  I couldn't find them.  Would they be more appropriately added to Modules/constants.f90 instead of my subroutine in PHonon/PH/dynmat.f90?

I'll be happy to commit the changes once I get feedback on the above question.

--William

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  William D. Parker              phone: +1 (630) 252-3388
  Argonne Scholar
  Argonne Leadership Computing Facility
  Building 240, Office 1-D.26
  Argonne National Laboratory
  9700 S. Cass Ave.
  Argonne, IL 60439
  U.S.A.
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