Dear developers:<div>I found a confusing thing.</div><div><b>Maybe it is a bug.</b><br><br clear="all">I try ph.x in quantum espresso 4.2.</div><div>input file:</div><div>"</div><div><b> &INPUTPH</b></div><div>
<b> ............</b></div><div><div><b> ldisp = .true.,</b></div><div><b> nq1 = 4 ,</b></div><div><b> nq2 = 4 ,</b></div><div><b> nq3 = 4 ,</b></div><div><b> ............</b></div></div><div>
"</div><div>output file:</div><div>"</div><div><div><b> reciprocal axes: (cart. coord. in units 2 pi/a_0)</b></div><div><b> b(1) = ( 1.0000 -1.0000 0.0000 ) </b></div><div><b> b(2) = ( 0.0000 1.0000 1.7426 ) </b></div>
<div><b> b(3) = ( -1.0000 0.0000 1.7426 ) </b></div><div><br></div></div><div><div><b> Dynamical matrices for ( 4, 4, 4,) uniform grid of q-points</b></div><div><b> ( 13q-points):</b></div><div>
<b> N xq(1) xq(2) xq(3) </b></div>
<div><b> 1 0.000000000 0.000000000 0.000000000</b></div><div><b> 2 -0.250000000 0.000000000 0.435659282</b></div><div><b> 3 0.500000000 0.000000000 -0.871318563</b></div><div><b> 4 -0.250000000 0.250000000 0.871318563</b></div>
<div><b> 5 0.500000000 0.250000000 -0.435659282</b></div><div><b> 6 0.250000000 0.250000000 0.000000000</b></div><div><b> 7 0.500000000 -0.500000000 -1.742637127</b></div><div><b> 8 0.000000000 0.000000000 0.871318563</b></div>
<div><b> 9 0.750000000 0.000000000 -0.435659282</b></div><div><b> 10 0.500000000 0.000000000 0.000000000</b></div><div><b> 11 0.750000000 -0.750000000 -1.742637127</b></div><div><b> 12 0.500000000 -0.500000000 -0.871318563</b></div>
<div><b> 13 0.000000000 0.000000000 -1.742637127</b></div></div><div>"</div><div>I can understand the above output information.</div><div><br></div><div>And I try another input method:</div><div>"</div>
<div><div><b> &INPUTPH</b></div><div><b> ............</b></div><div><div><b> ldisp = .true.,</b></div><div><b> nq1 = 4 ,</b></div><div><b> nq2 = 4 ,</b></div><div><b> nq3 = 4 ,</b></div>
</div>
<div><b> iq1 = 4 ,</b></div><div><b> iq2 = 2 ,</b></div><div><b> iq3 = 2 ,</b></div><div><b> ............</b></div></div><div>"</div><div>output file:</div><div>"</div><div><div><b> reciprocal axes: (cart. coord. in units 2 pi/a_0)</b></div>
<div><b> b(1) = ( 1.0000 -1.0000 0.0000 ) </b></div><div><b> b(2) = ( 0.0000 1.0000 1.7426 ) </b></div><div><b> b(3) = ( -1.0000 0.0000 1.7426 ) </b></div><div><b><br></b></div>
</div><div><b> Computing dynamical matrix for </b></div><div><div><b> q = ( 0.5000000 0.5000000 0.5000000 )</b></div><div><br></div></div><div>"</div><div>Howver, I failed to understand the <b> q = ( 0.5000000 0.5000000 0.5000000 )</b>.</div>
<div><b><br></b></div><div><b>"q = ( 0.5000000 0.5000000 0.5000000 )" </b>does not appear in the 13 q points:</div><div><b><span class="Apple-style-span" style="font-weight: normal; "><div><b> Dynamical matrices for ( 4, 4, 4,) uniform grid of q-points</b></div>
<div><b> ( 13q-points):</b></div><div><b> N xq(1) xq(2) xq(3) </b></div><div><b> 1 0.000000000 0.000000000 0.000000000</b></div><div><b> 2 -0.250000000 0.000000000 0.435659282</b></div>
<div><b> 3 0.500000000 0.000000000 -0.871318563</b></div><div><b> 4 -0.250000000 0.250000000 0.871318563</b></div><div><b> 5 0.500000000 0.250000000 -0.435659282</b></div><div><b> 6 0.250000000 0.250000000 0.000000000</b></div>
<div><b> 7 0.500000000 -0.500000000 -1.742637127</b></div><div><b> 8 0.000000000 0.000000000 0.871318563</b></div><div><b> 9 0.750000000 0.000000000 -0.435659282</b></div><div><b> 10 0.500000000 0.000000000 0.000000000</b></div>
<div><b> 11 0.750000000 -0.750000000 -1.742637127</b></div><div><b> 12 0.500000000 -0.500000000 -0.871318563</b></div><div><b> 13 0.000000000 0.000000000 -1.742637127</b></div></span></b></div>
<div><b>Does is a bug?</b></div><div><br></div><div>Bye the way, do all these q points are given in the <b>(cart. coord. in units 2 pi/a_0)</b>?</div><div><br></div><div><br></div><div>-- <br>____________________________________<br>
Hui Wang<br>School of physics, Nankai University, Tianjin, China<br>
</div>