IP level absorption spectra of CH4

[joydev.asadtala]

Dear Sir,
I have done the IP level absorption spectra of CH4. According to the theory, the first peak of the spectra should come at the energy different between occupied and unoccupied energy level of the scf energy. But it is not coming. The first peak come at lower energy than the energy different. I have attached the scf.in, scf.out, spectra file, yambo.in, & LOG folder.

Sincerely,
Joydev De
PhD student, NISER, India

[Daniele Varsano]

Dear Joydev,

please sign your post with your name and affiliation, this is a rule of the forum and you can do it once for all by filling the signature in your user profile.

Can you please post the report and input file of your calculation?

Please have in mind that the usual procedure for the yambo setup is:
1) SCF for the ground state
2) NSCF adding empty states (note you are using very few empty states, anyway this is unrelated to your problem)
3) P2Y


Best,
Daniele