<div dir="ltr"><div>If you compile QE with HDF5 support, binary data files are written in HDF5 and readable using external software (e.g. python scripts). Fortran binaries are readable only from fortran.<br></div><div><br></div><div>Paolo<br> </div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Sep 20, 2021 at 8:24 PM Tharindu W-fernando via users <<a href="mailto:users@lists.quantum-espresso.org">users@lists.quantum-espresso.org</a>> wrote:<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>Hello Everyone,</div><div><br></div><div>The common interband matrix element <m| dH/dkx \pm i dH\dky |n> seems to be calculable using DFT software. However, I am trying to calculate the tangential matrix element <m| dH/dt | n> \equiv <m| dH/dkx dkx/dt + dH/dky dky/dt |n> for some parameter t that parameterizes a closed loop in k-space: (kx(t),ky(t)) = (kx0+cos(t), ky0+sin(t)), where the loop center is (kx0,ky0). With my basic understanding of QE, I thought of a way to do this using a monolayer MoS2 example: <br></div><div>I first sample k-points along a closed loop. This gives me wavefunctions in the .dat format. I was hoping to somehow extract wavefunction data to smoothen the gauge using the maximally localized Wannier function method, and manually calculate the matrix element I want using a central difference method with MATLAB or Python. <br></div><div>However, I cannot seem to read the data from the .dat files. I saw several solutions in the archives that suggest using different existing routines that involve the evec variable. However, I am not familiar with Fortran90 and so have trouble figuring out how exactly to use such routines and custom code to get eigenvector data in a readable format. Does anyone have any advice or resources? I am using QE v6.6<br></div><div>Alternatively, are there other more-direct ways to go about calculating the quantity I want? <br></div><div>Thank you very much for your time!</div><div><br></div><div>Tharindu W. Fernando</div><div>PhD Student, University of Washington<br></div><div><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>Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,<br>Univ. Udine, via delle Scienze 206, 33100 Udine, Italy<br>Phone +39-0432-558216, fax +39-0432-558222<br><br></div></div></div></div></div>