<div dir="ltr">Dear Mohamed khuili,<br><br>your problem is not fully clear to me. Do you mean the lattice vectors change in a CELL_OPT run compared to plain DFT when you apply DFT+U instead of plain DFT?<br><br>Best,<br><br>Matthias<br><br>On Wednesday, 25 June 2014 04:16:28 UTC+2, mohamed khuili  wrote:<blockquote class="gmail_quote" style="margin: 0;margin-left: 0.8ex;border-left: 1px #ccc solid;padding-left: 1ex;"><div dir="ltr"><span lang="en"><span>Hello</span><span>I am working on</span> <span>the</span> <span>ZnO</span><br> <span>I want to apply</span> <span>DFT</span> <span>+</span> <span>U,</span> <span>but when</span> <span>I see</span> <span>the output file</span> <span>I find that the</span> <span>parameters</span> <span>of the mesh</span> <span>they</span> <span>down,</span> <span>how can I</span> <span>apply the</span> <span>corrections</span> <span>without significantly</span> <span>affect</span> <span>the parameters</span> <span>of the cell</span> <span>obtained by</span> <span>DFT</span><br> <span>thank you</span> <span>very much</span></span></div></blockquote></div>