[Wien] another space group question : hexagonal to orthorhombic

[Peter Blaha]

DO you use the latest version of LAPW0 ? I think I even announced this bugfix
on the mailing list. Have a look at   http://www.wien2k.at/reg_user/updates

# 26.11.2003: SRC_lapw0/latgen.f: Fix of a serious bug for GGA-calculations for CXY lattices.


> In order to make deformations, I have built an orthorhombic structure
> file (#63 Cmcm) which is equivalent to an hexagonal one (#194 P63/mmc).
> The orthorhombic cell has double volume and is centered. The hex cell
> basis is (a, b=a, c) and the ortho (a, a+2b, c)/
> I have extensively checked both structures and can't find difference.
> They both have same volume, atoms are in same positions and all other
> parameters are identical (kpts, RMT, RKM,...).
> In both cases the calculation runs smoothly.
> However I get 0.1 Ryd difference in total energy between the two
> structures, which seems to me way too large.
> I am puzzled.


                                      P.Blaha
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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/
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