<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div>On Jan 4, 2009, at 12:38 AM, Paul M. Grant wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>Followup on K_POINTS: tpiba vs crystal...</div></blockquote><div><br></div>Hi Paul!</div><div><br><blockquote type="cite"><div>As usual, Paolo is right...</div></blockquote><div><br></div>he always does!</div><div><br><blockquote type="cite"><div>for sc lattices (ibrav=1), tpiba or crystal give<br>equal nscf outputs.</div></blockquote><div><br></div>no surprise, here</div><div><br><blockquote type="cite"><div>But, for fcc lattices (ibrav=2), it apparently does! </div></blockquote><div><br></div>you mean it does NOT .?... no surprise here either ...</div><div><br><blockquote type="cite"><div>See below comparing<br>nscf k-vector outputs for tpiba and crystal, and crystal is very different<br>(and weird...for me anyway). </div></blockquote><div><br></div>I am not sure I understand what the question really is, but I do not what would weird here.</div><div><br></div><div>My understanding is that "tpiba" means "cartesian coordinates in units of tipiba". By the way, it could be a good idea to replace "tpiba" (a word that does exist in the webster nor in any other dictionary) with "cartesian": this could help avoid some confusion. "crystal" means that the coordinates that you give are the coefficient that express a k-point as a linear combination of the reciprocal lattice basis g(1), g(2), g(3). In formulas:</div><div><br></div><div>k("tpiba") = tpiba * (k(1)*x(1)+k(2)*x(2)+k(3)*x(3))</div><div>k("crystal") = tpiba* (k(1)*b(1)+k(2)*b(2)+k(3)*b(3)),</div><div><br></div><div>where x(1)= (1,0,0), x(2)=(0,1,0), x(3)=(0,0,1), and the slightly confusing tpiba in the second line is due to the code convention: g(*)=tpiba*b(*)</div><div><br></div><div>Let us take for instance the second vector of Paul's list. In the "tpiba" case, the output is just a copy of the input, as it should. In the crystal case, one should have:</div><div><br></div><div>output(*) = input(1)*b(1) + input(2)*b(2)+input(3)*b(3)</div><div> = -1/12 (-1,-1,1) +1/12 (1,1,1)-1/12(-1,1,-1)</div><div> = 1/12 (1+1+1,1+1-1,-1+1+1)</div><div> = (1/4,1/12,1/12),</div><div><br></div><div>which is what it is. I have noot checked the other points, but I assume that they are what they should be according to the above argument</div><div><br><blockquote type="cite"><div>BTW, whether tpiba, etc., should be enclosed<br>in curly braces or parentheses or nothing on the K_POINTS card is confusing.<br>PW_INPUT shows braces, but parenthese work too, and probably no delimiters<br>as well.</div></blockquote><div><br></div>sorry, no hints here ...</div><div><br><blockquote type="cite"><div>My agenda here is to generate k-points grids amenable to applications that<br>cannot use simply MP weighted points in the irreducible BZ, such as<br>epsilon.x. I'm finding the algorithm used by Eyvaz Isaev for Fermi Surface<br>plotting which uniformly populate and span the fundamental reciprocal<br>lattice cell works quite well...if inputted with tpiba or "blank," not<br>crystal.</div></blockquote><div><br></div>most probably, it give the cartesian representation of the k-points ...</div><div><br></div><div>hope the above is not (too) wrong and helpful to some extent ...</div><div><br></div><div>Happy new year to Paul, Paolo, and the whole newsgroup.</div><div><br></div><div>Stefano</div><div><br><blockquote type="cite"><div><br><br><br>TPIBA VS CRYSTAL COMPARISON RE FCC FOLLOWS<br>=================================================== <br>TPIBA<br>nsfc run input (partial) (Al, ibrav=2)<br>K_POINTS {tpiba}<br> 2197<br> 0.00000000 0.00000000 0.00000000 1.00000000<br> -0.08333333 0.08333333 -0.08333333 1.00000000<br> -0.16666667 0.16666667 -0.16666667 1.00000000<br> -0.25000000 0.25000000 -0.25000000 1.00000000<br> -0.33333333 0.33333333 -0.33333333 1.00000000<br> -0.41666667 0.41666667 -0.41666667 1.00000000<br> -0.50000000 0.50000000 -0.50000000 1.00000000<br> -0.58333333 0.58333333 -0.58333333 1.00000000<br> -0.66666667 0.66666667 -0.66666667 1.00000000<br> -0.75000000 0.75000000 -0.75000000 1.00000000<br> -0.83333333 0.83333333 -0.83333333 1.00000000<br> -0.91666667 0.91666667 -0.91666667 1.00000000<br> -1.00000000 1.00000000 -1.00000000 1.00000000<br> 0.08333333 0.08333333 0.08333333 1.00000000<br> 0.00000000 0.16666667 0.00000000 1.00000000<br> -0.08333333 0.25000000 -0.08333333 1.00000000<br> -0.16666667 0.33333333 -0.16666667 1.00000000<br> -0.25000000 0.41666667 -0.25000000 1.00000000<br> -0.33333333 0.50000000 -0.33333333 1.00000000<br>....................<br>nsfc run output (partial) (Al, ibrav=2)<br>reciprocal axes: (cart. coord. in units 2 pi/a_0)<br> b(1) = ( -1.000000 -1.000000 1.000000 ) <br> b(2) = ( 1.000000 1.000000 1.000000 ) <br> b(3) = ( -1.000000 1.000000 -1.000000 ) <br>number of k points= 2197 gaussian broad. (Ry)= 0.0150 ngauss = 0<br> cart. coord. in units 2pi/a_0<br> k( 1) = ( 0.0000000 0.0000000 0.0000000), wk = 0.0009103<br> k( 2) = ( -0.0833333 0.0833333 -0.0833333), wk = 0.0009103<br> k( 3) = ( -0.1666667 0.1666667 -0.1666667), wk = 0.0009103<br> k( 4) = ( -0.2500000 0.2500000 -0.2500000), wk = 0.0009103<br> k( 5) = ( -0.3333333 0.3333333 -0.3333333), wk = 0.0009103<br> k( 6) = ( -0.4166667 0.4166667 -0.4166667), wk = 0.0009103<br> k( 7) = ( -0.5000000 0.5000000 -0.5000000), wk = 0.0009103<br> k( 8) = ( -0.5833333 0.5833333 -0.5833333), wk = 0.0009103<br> k( 9) = ( -0.6666667 0.6666667 -0.6666667), wk = 0.0009103<br> k( 10) = ( -0.7500000 0.7500000 -0.7500000), wk = 0.0009103<br> k( 11) = ( -0.8333333 0.8333333 -0.8333333), wk = 0.0009103<br> k( 12) = ( -0.9166667 0.9166667 -0.9166667), wk = 0.0009103<br> k( 13) = ( -1.0000000 1.0000000 -1.0000000), wk = 0.0009103<br> k( 14) = ( 0.0833333 0.0833333 0.0833333), wk = 0.0009103<br> k( 15) = ( 0.0000000 0.1666667 0.0000000), wk = 0.0009103<br> k( 16) = ( -0.0833333 0.2500000 -0.0833333), wk = 0.0009103<br>============================================================================<br>CRYSTAL<br>nsfc run input (partial) (Al, ibrav=2)<br>K_POINTS {crystal}<br> 2197<br> 0.00000000 0.00000000 0.00000000 1.00000000<br> -0.08333333 0.08333333 -0.08333333 1.00000000<br> -0.16666667 0.16666667 -0.16666667 1.00000000<br> -0.25000000 0.25000000 -0.25000000 1.00000000<br> -0.33333333 0.33333333 -0.33333333 1.00000000<br> -0.41666667 0.41666667 -0.41666667 1.00000000<br> -0.50000000 0.50000000 -0.50000000 1.00000000<br> -0.58333333 0.58333333 -0.58333333 1.00000000<br> -0.66666667 0.66666667 -0.66666667 1.00000000<br> -0.75000000 0.75000000 -0.75000000 1.00000000<br> -0.83333333 0.83333333 -0.83333333 1.00000000<br> -0.91666667 0.91666667 -0.91666667 1.00000000<br> -1.00000000 1.00000000 -1.00000000 1.00000000<br> 0.08333333 0.08333333 0.08333333 1.00000000<br> 0.00000000 0.16666667 0.00000000 1.00000000<br> -0.08333333 0.25000000 -0.08333333 1.00000000<br> -0.16666667 0.33333333 -0.16666667 1.00000000<br> -0.25000000 0.41666667 -0.25000000 1.00000000<br> -0.33333333 0.50000000 -0.33333333 1.00000000<br> -0.41666667 0.58333333 -0.41666667 1.00000000<br>...................<br>nsfc run output (partial) (Al, ibrav=2)<br>reciprocal axes: (cart. coord. in units 2 pi/a_0)<br> b(1) = ( -1.000000 -1.000000 1.000000 ) <br> b(2) = ( 1.000000 1.000000 1.000000 ) <br> b(3) = ( -1.000000 1.000000 -1.000000 ) <br> number of k points= 2197 gaussian broad. (Ry)= 0.0150 ngauss = <br> cart. coord. in units 2pi/a_0<br> k( 1) = ( 0.0000000 0.0000000 0.0000000), wk = 0.0009103<br> k( 2) = ( 0.2500000 0.0833333 0.0833333), wk = 0.0009103<br> k( 3) = ( 0.5000000 0.1666667 0.1666667), wk = 0.0009103<br> k( 4) = ( 0.7500000 0.2500000 0.2500000), wk = 0.0009103<br> k( 5) = ( 1.0000000 0.3333333 0.3333333), wk = 0.0009103<br> k( 6) = ( 1.2500000 0.4166667 0.4166667), wk = 0.0009103<br> k( 7) = ( 1.5000000 0.5000000 0.5000000), wk = 0.0009103<br> k( 8) = ( 1.7500000 0.5833333 0.5833333), wk = 0.0009103<br> k( 9) = ( 2.0000000 0.6666667 0.6666667), wk = 0.0009103<br> k( 10) = ( 2.2500000 0.7500000 0.7500000), wk = 0.0009103<br> k( 11) = ( 2.5000000 0.8333333 0.8333333), wk = 0.0009103<br> k( 12) = ( 2.7500000 0.9166667 0.9166667), wk = 0.0009103<br> k( 13) = ( 3.0000000 1.0000000 1.0000000), wk = 0.0009103<br> k( 14) = ( -0.0833333 0.0833333 0.0833333), wk = 0.0009103<br> k( 15) = ( 0.1666667 0.1666667 0.1666667), wk = 0.0009103<br> k( 16) = ( 0.4166667 0.2500000 0.2500000), wk = 0.0009103<br> k( 17) = ( 0.6666667 0.3333333 0.3333333), wk = 0.0009103<br> k( 18) = ( 0.9166667 0.4166667 0.4166667), wk = 0.0009103<br> k( 19) = ( 1.1666667 0.5000000 0.5000000), wk = 0.0009103<br> k( 20) = ( 1.4166667 0.5833333 0.5833333), wk = 0.0009103<br> k( 21) = ( 1.6666667 0.6666667 0.6666667), wk = 0.0009103<br><br>Paul M. Grant, PhD<br>Principal, W2AGZ Technologies<br>Visiting Scholar, Applied Physics, Stanford (2005-2008)<br>EPRI Science Fellow (Retired)<br>IBM Research Staff Member Emeritus<br><a href="mailto:w2agz@pacbell.net">w2agz@pacbell.net</a><br>http://www.w2agz.com<br> <br> <br><br><br>-----Original Message-----<br>From: pw_forum-bounces@pwscf.org [mailto:pw_forum-bounces@pwscf.org] On<br>Behalf Of Paolo Giannozzi<br>Sent: Tuesday, December 30, 2008 5:21 AM<br>To: PWSCF Forum<br>Subject: Re: [Pw_forum] K_POINTS, tpiba or crystal<br><br>On Tuesday 30 December 2008 05:56, Paul M. Grant wrote:<br><br><blockquote type="cite"> b(1) = ( 1.000000 0.000000 0.000000 )<br></blockquote><blockquote type="cite"> b(2) = ( 0.000000 1.000000 0.000000 )<br></blockquote><blockquote type="cite"> b(3) = ( 0.000000 0.000000 1.000000 )<br></blockquote><br>these are the lattice vectors generating a simple cubic lattice<br><br><blockquote type="cite">Now, I want to input this grid to an nscf run via K_POINTS...is my grid<br></blockquote><blockquote type="cite">"tpiba" or "crystal?"<br></blockquote><br>in this particular case, it shouldn't matter, since the crystal and<br>cartesian axis are the same, and the length of crystal axis is 2pi/a .<br><br>Paolo<br>-- <br>Paolo Giannozzi, Democritos and Udine University<br>_______________________________________________<br>Pw_forum mailing list<br>Pw_forum@pwscf.org<br>http://www.democritos.it/mailman/listinfo/pw_forum<br><br>_______________________________________________<br>Pw_forum mailing list<br>Pw_forum@pwscf.org<br>http://www.democritos.it/mailman/listinfo/pw_forum<br></div></blockquote></div><br><div apple-content-edited="true"> <span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; 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: 0; "><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: 14px; 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: 14px; 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: 14px; 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; "><div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; ">---</span></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; ">Stefano Baroni - SISSA</span></font><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; "> </span></font><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; ">&</span></font><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; "> </span></font><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; ">DEMOCRITOS National Simulation Center - Trieste</span></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; "><a href="http://www.sissa.it/~baroni">http://www.sissa.it/~baroni</a> / [+39] 040 3787 406 (tel) -528 (fax) / stefanobaroni (skype)</span></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Helvetica; min-height: 14px; font-size: 12px; "><br style="font-size: 12px; "></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Helvetica; min-height: 14px; font-size: 12px; "><span class="Apple-style-span" style="font-size: 14px; "><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; ">La morale est une logique de l'action comme la logique est une morale de la pensée - Jean Piaget</span></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; "><br></span></font></div></span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; ">Please, if possible, don't</span></font><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; "> </span></font><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; ">send me MS Word or PowerPoint attachments</span></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; ">Why? See:</span></font><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; "> </span></font><font class="Apple-style-span" color="#0023E9" size="3"><span class="Apple-style-span" style="font-size: 12px; "><a href="http://www.gnu.org/philosophy/no-word-attachments.html">http://www.gnu.org/philosophy/no-word-attachments.html</a></span></font></div><div><font class="Apple-style-span" color="#0023E9" size="3"><span class="Apple-style-span" style="font-size: 12px; "><br class="webkit-block-placeholder"></span></font></div></div></div></span><br class="Apple-interchange-newline"></div></span><br class="Apple-interchange-newline"></div></span><br class="Apple-interchange-newline"></div></span><br class="Apple-interchange-newline"> </div><br></body></html>