<div dir="ltr"><div dir="ltr">Dear Wien2k users,<div><br></div><div>I am trying to unfold a hexagonal 2x2x2 superlattice with fold2bloch tool, but I am having difficulty with getting the right k-path. As my path is rather complicated (GAMMA->M(1/2 0 0)->K(1/3 1/3 1/3)->GAMMA->A(0 0 1/2)->L(1/2 0 1/2)->H(1/3 1/3 1/3)->A(0 0 1/2)), I tried to use the script which was previously advised here (fold.m)</div><div><div><pre style="font-family:courier,"courier new",monospace;font-size:14px;white-space:pre-wrap;margin:0em;color:rgb(0,0,0)"><a rel="nofollow" href="https://github.com/rubel75/fold2Bloch-VASP/blob/master/utils/fold.m" style="outline:0px;color:rgb(57,115,66)">https://github.com/rubel75/fold2Bloch-VASP/blob/master/utils/fold.m</a></pre></div></div><div>in the following message:</div><div><a href="https://www.mailarchive.com/wien@zeus.theochem.tuwien.ac.at/msg18482.html">https://www.mailarchive.com/wien@zeus.theochem.tuwien.ac.at/msg18482.html</a> </div><div>However, this doesn't work properly (I'm having empty gaps in the unfolded diagram). I tried a much simpler path, like M->GAMMA->K, with the following input:</div><div><br></div><div><div>%% User input</div><div><br></div><div>kpath = [1/2 0 0; 0 0 0; 1/3 1/3 0]; % desired k-path after unfolding</div><div>npath = [16 16]; % # of points along each segment</div><div>folds = [2 2 2]; % multiplicity used to create a supercell</div><div><br></div><div>but this also results is a strange list of k-points:</div><div><br></div><div> 1 0 0 0 1 1.00<br> 2 -1 0 0 15 1.00<br> 3 -2 0 0 15 1.00<br> 4 -1 0 0 5 1.00<br> 5 -4 0 0 15 1.00<br> 6 -1 0 0 3 1.00<br> 7 -2 0 0 5 1.00<br> 8 -7 0 0 15 1.00<br> 9 7 0 0 15 1.00<br> 10 2 0 0 5 1.00<br> 11 1 0 0 3 1.00<br> 12 4 0 0 15 1.00<br> 13 1 0 0 5 1.00<br> 14 2 0 0 15 1.00<br> 15 1 0 0 15 1.00<br> 16 2 2 0 45 1.00<br> 17 4 4 0 45 1.00<br> 18 2 2 0 15 1.00<br> 19 8 8 0 45 1.00<br> 20 2 2 0 9 1.00<br> 21 4 4 0 15 1.00<br> 22 14 14 0 45 1.00<br> 23 16 16 0 45 1.00<br> 24 2 2 0 5 1.00<br> 25 4 4 0 9 1.00<br> 26 22 22 0 45 1.00<br> 27 -7 -7 0 15 1.00<br> 28 -19 -19 0 45 1.00<br> 29 -17 -17 0 45 1.00<br> 30 -1 -1 0 3 1.00<br></div><div><br></div><div>First 15 points seem to be fine, it goes from GAMMA (0,0) to -M (
-7/15, 0, 0) and then from M(7/15, 0, 0) back to GAMMA (1/15, 0, 0). However, the next part it doesn' go to K point (1/3, 1/3, 0), but rather overshoots (22/45, 22/45, 0), and there are only 4 points on the negative side, while points between (-1/3 -1/3 0) and (0 0 0) are missing. It seems to me that something is wrong here. Can someone comment if this is a correct output? I did the same part of the path -K -> GAMMA -> K with XCrysDen and it goes from (-1/3 -1/3 0) to (1/3 1/3 0) without any gaps, and this seems to be reasonable but it doesn't agree well with the output of fold.m.</div><div><br></div><div>I'm not familiar with Matlab, but it seems to me that fold.m doesn't work with a hexagonal lattice nor with more complicated paths like (0 0 0 -> 1/2 0 0 -> 1/3 1/3 0 -> 0 0 0). Can someone suggest how I can get the right path? I suppose I can manually split the whole path into segments in XCrysDen and stitch them all together
manually, but then how to treat points which are not going through GAMMA, but which are on the surface of BZ, like M->K? Shall I include a path which goes symmetrically around a* reciprocal lattice vector or rather symmetrically around GAMMA (-K -> M -> K or -K -> -M)? If I will generate a proper k-path manually, is it going to work with fold2bloch and ubs_dots_w2k_octave.m or is it also going to cause some troubles when plotting sections which are at the surface of BZ? </div><div><br></div><div><br></div><div>Best regards,</div><div>Weronika</div><div><br></div>-- <br><div dir="ltr" class="gmail_signature"><div dir="ltr">Weronika Wiktoria Wolszczak<div>Postdoctoral researcher <br></div><div>TU Delft/Wake Forest University</div><div><a href="https://www.linkedin.com/in/weronika-wolszczak-6a8087a2" target="_blank">LinkedIn</a>/<a href="https://www.researchgate.net/profile/Weronika_Wolszczak" target="_blank">Research Gate</a>/<a href="https://scholar.google.com/citations?user=RKjzu0EAAAAJ&hl=en&oi=ao" target="_blank">Google Scholar</a><br></div></div></div></div></div></div>