Warning in the case of a complex diagonal hybridization

[mzingl]

Hi,

currently the solver accepts diagonal hybridizations with a complex part. These are forced to be real.
Can we have a sanity check / warning for the case where an erroneous hybridization is passed to the solver?

Thanks,
Manuel

[mzingl]

To be bit more precise:
Since the improvement on the tail-fitting of complex Gf I (and others) sometimes get the following error in cases where no complex tailfit is needed:

.. Error .. calling C++ overload
.. fit_tail(tail_view known_moments, int max_moment, int n_min, int n_max, bool replace_by_fit) -> void
.. in implementation of method GfImFreq.fit_tail
.. C++ error was :
.. Triqs runtime error at /home/mzingl/Tools/TRIQS/src/triqs/gfs/singularity/fit_tail.cpp : 187
more arguments are needed to fit a complex gf

The real cause of the error is however a tiny imaginary part of Delta(tau), which can grow slowly with the DMFT iterations. The real version of the cthyb solver neglects these imaginary parts. Although, it is neglected in Delta(tau) it will be still present in the self-energy. Thus, it happens that it grows from machine precision to the threshold where the tailfit starts to use the complex version. As this is not really an issue with the tailfit, the resulting error is very confusing.

Best,
Manuel

[HugoStrand]

This issue should be fixed by the update in the tail fitting routines. Please repoen if the issue persists.