The cells are same size and the cutoff is also same. The difference is that in the second cell I used a pseudopotential generated by virtual.x (the pp mix N.*.UPF and O.*.UPF), in the other words, i used the virtual crystal approximation method to simulate the SRO system doped by nitrogen.<div>
<br></div><div>Best wishes!<br><br><div class="gmail_quote">2012/9/18 Gabriele Sclauzero <span dir="ltr"><<a href="mailto:gabriele.sclauzero@epfl.ch" target="_blank">gabriele.sclauzero@epfl.ch</a>></span><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div style="word-wrap:break-word"><br><div><div>Il giorno 18/set/2012, alle ore 14.55, Yue-Wen Fang ha scritto:</div><div><div class="h5"><br><blockquote type="cite">Dear all,<div>It happened a problem to me when calculating the charge density difference. </div>
<div><b>My input</b>:</div><div><div>&inputpp</div><div>/</div><div>&plot</div><div>nfile = 2</div><div>    filepp(1) = 'SRO-up.rho'   <b>(SRO-up.rho is a file which records the charge density data of this system, it was given at last step)</b></div>

<div>    filepp(2) = 'SROup-doping.rho'</div><div>    weight(1) = 1.0</div><div>    weight(2) = -1.0</div><div>    iflag = 2</div><div>    output_format = 3</div><div>    fileout = 'test_diff.xsf'</div><div>

e1(1) =1.0, e1(2)=0.0, e1(3) = 0.0,</div><div>e2(1) =0.0, e2(2)=0.0, e2(3) = 1.0,</div><div>x0(1) =0.0, x0(2)=0.50, x0(3) = 0.0,</div><div>nx=56, ny=40</div><div>/</div><div><b>The output</b>:</div><div><div>     R & G space division:  proc/pool =    4</div>

<div>     Reading header from file  SRO-up.rho</div><div>     Reading data from file  SRO-up.rho</div><div><br></div><div> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</div><div>     from chdens : error #         1</div>

<div>     <b>incompatible nr1x or nr2x    (I haven't found what nr1x means)</b></div><div> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</div><div><br></div><div>     stopping ...</div>
</div></div></blockquote><br></div></div></div><div>Most probably there is a size mismatch between the two cells, or you used a different cutoff for the two calculations. Please check.</div><div><br></div><div><br></div><div>
GS</div><div><br></div><div><br></div><br><div>
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<div><span style="color:rgb(126,126,126);font-size:16px;font-style:italic"><br>§ Gabriele Sclauzero, EPFL SB ITP CSEA</span></div><div><font color="#7E7E7E"><i>   PH H2 462, Station 3, CH-1015 Lausanne</i></font></div></div>
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<br></blockquote></div><br><br clear="all"><div><br></div>-- <br>----<div>Yue-Wen Fang</div><div><br></div><div><br></div><br>
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