<div>Dear Palo Giannozzi:</div>
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<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid"><font color="#550055">></font>and I am fed up with people who can't sort out even the tiniest<br><font color="#550055">></font>and most trivial detialsdetails. </blockquote>
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<div>I am very sorry for bothering you.</div>
<div>Please forgive me.</div></div><br>
<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid"><font color="#550055">></font>Force constants have two atom<br><font color="#550055">></font>indices, two polarization indices, depend upon lattice vectors.</blockquote>
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<div>Take the "/espresso-4.0.4/examples/example06/results/alas444.fc" file for example.</div>
<div>" 4 4 4<br> 1 1 1 1<br> 1 1 1 2.24396850738E-01<br>"<br>I thinks the two polarization indices are <em>x</em> and <em>x</em>;</div>
<div> the two atoms indices are <em>1 and 1;</em></div>
<div><em> </em>the lattice vectors of the two atoms are <em>R1=0*a1+0*a2+0*a3 and R2=1*a1+1*a2+1*a3.</em>(a1,a2,a3 are the primitive lattice vectors in real space.)</div>
<div>Am i wrong?</div>
<div>Suppose I am right, what about the interaction terms for atom 1 and atom 2 in the zeroth unit cell?</div></div>
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<div>Once again, I am very sorry.</div>
<div>Happy holiday:)</div>
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<div>____________________________________<br>Hui Wang<br>School of physics, Nankai University, Tianjin, China </div></div>