[Wannier] Omega minimum search divergence in wannier90

[Alex Kutana]

Dear wannier90 developers:

I have encountered the following problem during the search for the minimum of omega in wannier90: 
at
some step of the minimum search, the next omega is predicted to be
smaller than the current one, whereas it turns out to be much larger, i.e. omega increases during the search.
Since
there seems to be no check on the actual (as opposed to predicted)
value of the new omega, the whole search routine blows up from there.

 The increase
in omega diagonal (O_D) occurs during step 3. Here are the values at the
beginning of step 3:

LINE --> Spread at initial point       :   49.8723128210178
LINE --> Spread at trial step          :   49.5779629623660
LINE --> Slope along search direction  : -0.156333808720867
LINE --> Trial step length             :   2.00000000000000
LINE --> Optimal parabolic step length :   17.0690978644447
LINE --> Spread at predicted minimum   :   48.5380742807289

However, at the end of the step:

O_D=     54.0158131 O_OD=      6.2368759 O_TOT=     77.7379108 <-- SPRD
Delta: O_D=  0.2895663E+02 O_OD= -0.1091029E+01 O_TOT=  0.2786560E+02 <-- DLTA,

i.e. the diagonal component of omega tilda increased by 29.0!
I
suspect it may also be a compiler issue, since I couldn't get wannier90
to run with gfortran on my machine, but it seems to run with no problem
with ifort.
Here is the link to the archive with my .win, .amn, .mmn, .eig, and .wout files:
http://www.mediafire.com/?zx2cvkelcmx

Thank you.

Alex Kutana