<div dir="ltr"><div>Dear Andrew,</div><div><br></div><div>I would first compute | \psi'_l > = U_lm | \psi_m> using some linear algebra routine (as done in the code in many places by summing over plane waves), then compute <br></div><div>H |\psi'_l > (e.g., using h_psi.f90), finally the product with < \psi'_n |.</div><div>HTH</div><div><br></div><div>Matteo<br></div><div><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">Il giorno mer 7 ott 2020 alle ore 04:27 Andrew Xu <<a href="mailto:andrewaccount@gmail.com">andrewaccount@gmail.com</a>> ha scritto:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div>Hi users,</div><div><br></div><div>I would like to compute < \psi_n | U^\dagger H U | \psi_m>, where H is the KS Hamiltonian, \psi_n, \psi_m are the KS orbitals, and U is some unitary operator, by modifying the source code (not done separately through a separate Python script, for example), and wanted to ask for some advice. I think I can get the \psi_n, \psi_m in reciprocal space, but am not sure how to get the bra-ket. <br></div><div><br></div><div>Best regards,</div><div>Andrew<br></div></div>
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<a href="https://lists.quantum-espresso.org/mailman/listinfo/users" rel="noreferrer" target="_blank">https://lists.quantum-espresso.org/mailman/listinfo/users</a></blockquote></div><br clear="all"><br>-- <br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div>Matteo Cococcioni<br></div><div>Department of Physics<br></div>University of Pavia<br>Via Bassi 6, I-27100 Pavia, Italy<br>tel +39-0382-987485<br><div>e-mail <a href="mailto:lucio.andreani@unipv.it" target="_blank">matteo.cococcioni@unipv.it</a></div></div></div></div></div></div></div></div>