The ABINIT Users Mailing List ( CLOSED )

[Walter Lambrecht <walter.lambrecht@case.edu>]

In Veithen et al. PRB 71, 125107 (2005) it is described how to calculate the
linear electro-optic 
tensor in the unclamped condition, i.e. including the piezoelectric
contribution under zero external 
stress. From eq. A15, it appears that what is needed is the Raman tensor, the
force in response
to strain internal strain tensor for the second term and the derivatives of 
the
high frequency dielectric  tensor  vs. strain components in the first term.
At present it appears like I would be able to extract all the necessary 
pieces from the anaddb results for the second term but not the first term. Are
the 
third derivatives of the type: two vs. electric field and one vs. strain being
calculated by abinit
and where can I find them in the DDB files? or what variable needs to be set 
in
the input 
to generate these? Or better, has this procedure been implemented in anadbb?
Alternatively is the anadbb capable of generating the elasto-optic tensor
directly?
Sincerely,  
Walter Lambrecht