EPW Forum

Dear all, I am running a GW-BSE-EPW workflow to compute exciton-polaron optical spectra. I have completed the following stages: - BerkeleyGW: epsilon → sigma → kernel → absorption (Q=0 and finite-Q BSE) - EPW Step 1: electron-phonon Wannier interpolation (epw1.in) - EPW Step 2: exciton-polaron optic ...

Hi all, I am comparing EPW absorption spectra across different bilayer systems and notice a difference in how the lines appear at low energy. My doubt is whether this is a real physical finding or a mistake. In Figure 1, the 300K line drops sharply around 1.1 eV (w.r.t. the y-axis limit). In Figure ...

Dear all, I would like to ask if there is any significant difference between the results obtained from EPW 5.9 and EPW 6.0 , particularly regarding the HDF5 build and exciton–phonon coupling implementation. The reason for my doubt is the appearance of an additional message in EPW 6.0 after s ...

Dear all, I performed EPW of Si with the tutorial files. Band Structure of bands.x and epw.x matched. But Phonon Dispersion of ph.x and epw.x didn't match neither magnitude or profile of the curves. I had also got the absorption co-efficient onset around 0.5 (Band Gap = 0.5115 eV). I have attached ...

Dear Sabya and Xiao, Thank you so much for your valuable suggestions! 1. I learned about the necessity of renormalisation, but I couldn't understand how it was implemented from the paper. In Python, I tried renormalising and got the subsequent result (which I don't think is the proper way to do it ...

Dear all,

The issue has been resolved. In the NSCF, I didn't include the extra bands. Sorry for the inconvenience caused.

Result

1. Band Structure

Dear all, I tried to calculate the Phonon-assisted Optical Absorption of MoS2. I faced an issue in the interpolation of the electronic and phononic band structure (using eig_read=.false.). I couldn't match the DFT band structure and phonon dispersion calculated via QE. Kindly assist me in getting ...

Dear All, I calculated Si mobility via EPW Summer School 2018 tutorial (Resistivity and Mobility) using a 100x100x100 k/q-mesh. Though the profile match, the amplitudes don’t match the tutorial. Kindly help me match the result (from paper: https://arxiv.org/abs/1803.05462) Attached: 1. My result si_m ...

Dear all, I’m studying Si optical absorption. Used scissor flag (0, 0.44 eV) in EPW instead of BGW eigenvalues; results don’t match tutorial. Attached: inputs, band structure, absorption plots. Kindly help me to match the results with the scissor flag. Attached 1. Bandstructure Si_BS_comparison.jpg 2 ...

Dear Xiao, Thank you for your detailed feedback and valuable suggestions regarding my EPW calculations. To address your points and update on my progress: Eigenvalue File: I had already used the si.eig file with 34 bands per block (attached in first post) Recalculation with Tutorial and Custom ...