<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On Mar 24, 2010, at 12:46 PM, Dimpy Sharma wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">
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<!-- Converted from text/plain format --><p><font size="2">Hi there,<br>
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I have submitted my input file for nscf calcuation with 22 kpoints ( for the first brilloiun zone from kpoint from k=0 to 0.47) however in the output file of nscf , it calcuates the eigenvalues at k points 0,0.148,0.2960..3.1076 .Thus while plotting the band diagram my kvectir range becomes upto 3.1076. May I know why it happen? and to calculate the eigenvalues only on the given kpoints in th input file?<br>
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Thanks<br>
<br>
Dimpy<br>
<br>
Dimpy Sharma(Msc Nanotechnology<br>
PhD)<br>
UCC<br>
Ireland</font>
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</blockquote></div><div><br class="webkit-block-placeholder"></div><div><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div>possible issues:</div><div><br></div><div>i) if the number of k-points in the output is greater than the number of k-points you specify in the input, then the issue can be related</div><div>to symmetries. Unless you explicitly specify nosym = .true. (in nscf) the code always "complete" the k-point list in such a way it gets</div><div>compatible with the symmetry operations</div><div><br></div><div>ii) you are just "reading" your k-points in different units than you expect. Indeed, when the codes prints out the eigenvalues at each</div><div>k-point, the coordinates of the latter are tpiba, namely, 2 * pi / a (where a is the lattice constant along the first direct lattice axis).</div><div>Therefore, if you give, in the input</div><div><div style="text-align: left;">K_POINTS {crystal}</div><div style="text-align: left;">0.0 0.0 0.5 1.0</div><div style="text-align: left;">then if the system is not cubic ad c is the lattice parameter along the third direct lattice axis, the coordinates found in the output</div><div style="text-align: left;">will be 0.5 *a / c</div><div style="text-align: left;">I think that the band structure calculation requires not to keep the original "crystal units", because if you want to compute the band structure</div><div style="text-align: left;">along a given path in the Brilluoin zone, you want to keep the relative dimension of different segments (e.g. L-Gamma, Gamma-X) and for</div><div style="text-align: left;">that you cannot use a different unit along different directions (as it would occur in crystal coordinates in non-cubic systems).</div><div style="text-align: left;"><br></div><div style="text-align: left;">giovanni</div></div><div><br></div><div>--</div><div><br></div><div><div>Giovanni Cantele, PhD</div><div>CNR-SPIN and Dipartimento di Scienze Fisiche</div><div>Universita' di Napoli "Federico II"</div><div>Complesso Universitario M. S. Angelo - Ed. 6</div><div>Via Cintia, I-80126, Napoli, Italy</div><div>Phone: +39 081 676910 - Fax: +39 081 676346</div><div>Skype contact: giocan74</div><div><br></div><div>ResearcherID: <a href="http://www.researcherid.com/rid/A-1951-2009">http://www.researcherid.com/rid/A-1951-2009</a></div><div>Web page: <a href="http://people.na.infn.it/~cantele">http://people.na.infn.it/~cantele</a></div><div> <a href="http://www.nanomat.unina.it">http://www.nanomat.unina.it</a></div></div></span></div></span></span>
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