<div>Dear Stefano Baroni<span id="_user_baroni@sissa.it" style="COLOR: #cc0060"> </span>and Gabriele Sclauzero:</div>
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<div>First of all, thank you very much for your detailed explanation :）</div>
<div>I think I fully undertand it.</div>
<div>First, the "kpoints.x" reduces the number of k-points according to parameter "ibrav". That means kpoints.x chooses the symmetry among 14 Bravais lattices. </div>
<div>Second, the "pw.x" checkes all symmetry operations within a given Bravais lattice determined by kpoints.x. That means pw.x determines the symmetry among 7 crystal systems. </div>
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<div>But, now I have a another question about bands.x.</div>
<div>In the instruction of <a name="id3716704"> bands.x, it says:</a></div>
<div>Presently it can calculate:<br> (a) The expectation value of the spin operator on each spinor wave-function.<br> (b) <em>The symmetry properties of each wavefunction</em>. </div>
<div>The instruction of parameter "lsym" says:</div>
<div>If .true. the bands are classified according to the irreducible representations of the small group of k. A file "filband".rap with the same format of "filband" is written.<br> </div>
<div>I want to know the symmetry properties obatained by "band.x" is based on 7 crystal systems, 14 Bravais lattices or 32 point groups.<br><br>Once again, thank you very much ：）</div>
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<div>____________________________________<br>Hui Wang<br>School of physics, Nankai University, Tianjin, China </div>