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<p>Dear Developers and Users,</p>
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<p>I am using QE to get the vibrational modes and electron-vibrational coupling matrix elements (analogue of electron-phonon coupling matrix elements) for PAH molecules (say benzene). </p>
<p>I used supercell and gamma only calculation. I want to print the raw electron-phonon coupling matrix elements gij-(band and mode resolved) to use them in first order correction to the wavefunction formula (<b>equation 19</b>), attached the link to pdf . </p>
<p><a href="https://physicspages.com/pdf/Quantum%20mechanics/First%20order%20non-degenerate%20perturbation%20theory.pdf" class="OWAAutoLink">https://physicspages.com/pdf/Quantum%20mechanics/First%20order%20non-degenerate%20perturbation%20theory.pdf</a><br>
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<p>In QE 7.1, one of the developers <b>H.Lee</b> has made a modified version of ph.x in the directory "<span>test-suite/not_epw_comp", which prints the g values in standard output (for comparison with epw) as:</span></p>
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<p><span><span>ibnd jbnd imode enk[eV] enk+q[eV] omega(q)[meV] |g|[meV]</span></span></p>
<p><span><br>
These g values are not raw, (some square modulus thing is happening in the source code "supp.f90'), and evetually it prints<span> absolute |g| which loose phase information. </span></span></p>
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<p><span><span>Is there a way to get raw electron-vibrational coupling matrix elements as:</span></span></p>
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<p><span><span><span>ibnd jbnd imode enk[eV] enk+q[eV] omega(q)[meV] <b>Real_g [meV] Im_g[meV]</b></span></span></span></p>
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<p><span><span>Going to <span>PH/elphon.f90 and modifying the source code to print the raw values has been suggested previosuly (<span> a thread from Fri, 14 Mar 2014</span>), where user get errors. If someone knows how to get the raw coupling matrix elements,
please reply.</span></span></span></p>
<p><span><span><br>
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<p><span><span><span></span>Best wishes,</span></span></p>
<p><span><span>Afifa Farhat<br>
</span></span></p>
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