[Wien] external electronic fields

[Peter Blaha]

> Thanks for your reply.  I have found that there have a optional parameters EFIELD for the perturbation electic field in the case.in0. 
> my question is how can i define the electric field direction and the meaning of he IEFIELD parameter?

Adding an external elecric field is an "experimental" feature of WIEN2k.

a) The field will always point in z direction
b) Since we need periodic boundary conditions, the field is of zig-zag 
shape, this implies that one must generate a large supercell in 
z-direction, so that one can hope to have a constrant E-filed at least 
over some length of the unit cell.  Large computational effort!!!!
c) It is given by an max amplitude of the field plus some fourier 
coefficients, which lead to some smoothening of the kink between 
increasing/decreasing field.

Please read the PRB paper mentioned in the UG.

                                      P.Blaha
--------------------------------------------------------------------------
Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
--------------------------------------------------------------------------