<html><body><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: #000000"><div>Dear Users and Developers,</div><div><span style="font-size: 12pt;">I'm trying to calculate the phonon and electron-phonon properties of a simple conventional superconductor. I followed the standard procedure using pw.x -> ph.x -> q2r -> matdyn.x -> lambda.x.</span><br></div><div>This led to an unexpected situation. In the elph_dir directory, the values in the elph.inp_lambda.X files are positive, and in the lambda.out file, I successfully calculated the lambda, omega_log and T_c values, which all seem correct. However, I encountered negative values in the <code>phonon.dos</code> file.</div><div><span style="font-size: 12pt;">My question is: why does the alpha2F generated from lambda.x has positive values while the phonon.dos has some negative values?</span></div><div><br data-mce-bogus="1"></div><div>Best Regards</div><div data-marker="__SIG_PRE__">Artur<br>---<br>Czestochowa University of Technology<br></div></div></body></html>