Dear All,
I'm doing some test calculations on bulk hexagonal CdSe. I want to
calculate the phonon dispersion.
(Im using the version of T. Archer, for LO-TO splitting and include BC in my
Siesta calculation.
The dielectric constants I use are from literature on measurements. )
I get perfect acoustic frequencies at 0.0 cm^(-1).
Lowest optical and highest optical frequency are underestimated by
max. 2 % from experiment. OK.
However, the mid-range frequencies are overestimated, up to 10%.
So would you think this is ok, or should I further investigate the source
of this discrepancy?
Greetings
Marcel Mohr
