[Wannier] phase of plot of wannier functions

[Carmine Autieri]

Dear all, 

I used wannier90 to calculate hopping parameters for my solid bulk and all is fine.
I used wannier90 to plot wannier functions and I visualized using xcrysden.
My problem is that phase of the wannier functions in the plot are not in agreement with the sign of hopping parameters.

I observed that the 'Maximum grid value' is always bigger than the module of the 'Minimum grid value' when I use the plot generated from wannier90. I thought that, to impose this condition, the phase of some wannier functions in the plot are changed. Somebody found similar problem?

Best
Thanks
Carmine