[Pw_forum] phonons by LDA+U

[Ezad Shojaee]

Hi
I have performed an LDA+U calculation for my case, seems to be OK(with a noticable improvement in the band gap). But when i tried to perform phonon calculation, it converged to meaningless figures(containing a lot of minus ones) that are not comparable to the LDA. The structure is relatively relaxed due to the forces and stresses(that should be reasonable, as I have used U_Progection_type=atomic)
Is there anything i should concern?
sorry for the basic question!
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