There are two choices. First, you'd better learn crystallography well, and calculate the CELL_PARAMTERS and atoms positions by yourself. Second, you can use the program spacegroup in ELK FP-LAPW code to find them.<br><div></div><br>At 2011-06-13 20:44:09£¬"zafar rasheed" <zafartariq2003@yahoo.com> wrote:<br> <blockquote id="isReplyContent" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid"><table border="0" cellpadding="0" cellspacing="0"><tbody><tr><td style="font: inherit;" valign="top"><br><br>
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<p class="yiv1957372711MsoNormal" style="MARGIN: 0in 0in 0pt; LINE-HEIGHT: normal"><span style="FONT-SIZE: 10pt; FONT-FAMILY: 'sans-serif'">Hi</span><span style="FONT-SIZE: 12pt; FONT-FAMILY: 'serif'"></span>
</p><p class="yiv1957372711MsoNormal" style="MARGIN: 0in 0in 0pt; LINE-HEIGHT: normal"><span style="FONT-SIZE: 10pt; FONT-FAMILY: 'sans-serif'"> </span><span style="FONT-SIZE: 12pt; FONT-FAMILY: 'serif'"></span>
</p><p class="yiv1957372711MsoNormal" style="MARGIN: 0in 0in 0pt; LINE-HEIGHT: normal"><span style="FONT-SIZE: 10pt; FONT-FAMILY: 'sans-serif'"> I am PhD scholar and using Quantum Espresso Software. I do not know how to create supercell from unit cell. I do not know how to set CELL PARAMETERS option when we set ibrav=0. We actually want to create nanotube. I hope that you will guide me about this.</span>
</p><p class="yiv1957372711MsoNormal" style="MARGIN: 0in 0in 0pt; LINE-HEIGHT: normal"><font face="Calibri" size="3"> </font>
</p><p class="yiv1957372711MsoNormal" style="MARGIN: 0in 0in 0pt; LINE-HEIGHT: normal"><span style="FONT-SIZE: 10pt; FONT-FAMILY: 'sans-serif'">Best Regards</span><span style="FONT-SIZE: 12pt; FONT-FAMILY: 'serif'"></span>
</p><p class="yiv1957372711MsoNormal" style="MARGIN: 0in 0in 0pt; LINE-HEIGHT: normal"><span style="FONT-SIZE: 10pt; FONT-FAMILY: 'sans-serif'"> </span><span style="FONT-SIZE: 12pt; FONT-FAMILY: 'serif'"></span>
</p><p class="yiv1957372711MsoNormal" style="MARGIN: 0in 0in 0pt; LINE-HEIGHT: normal"><span style="FONT-SIZE: 10pt; FONT-FAMILY: 'sans-serif'">Muhammad zafar</span><span style="FONT-SIZE: 12pt; FONT-FAMILY: 'serif'"></span>
</p><p class="yiv1957372711MsoNormal" style="MARGIN: 0in 0in 0pt; LINE-HEIGHT: normal"><span style="FONT-SIZE: 10pt; FONT-FAMILY: 'sans-serif'"> </span><span style="FONT-SIZE: 12pt; FONT-FAMILY: 'serif'"></span>
</p><p class="yiv1957372711MsoNormal" style="MARGIN: 0in 0in 0pt; LINE-HEIGHT: normal"><span style="FONT-SIZE: 10pt; FONT-FAMILY: 'sans-serif'">PhD scholar</span><span style="FONT-SIZE: 12pt; FONT-FAMILY: 'serif'"></span>
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</p><p class="yiv1957372711MsoNormal" style="MARGIN: 0in 0in 10pt"><span style="FONT-SIZE: 10pt; LINE-HEIGHT: 115%; FONT-FAMILY: 'sans-serif'">The </span><span style="FONT-SIZE: 10pt; LINE-HEIGHT: 115%; FONT-FAMILY: 'sans-serif'">Islamia University</span><span style="FONT-SIZE: 10pt; LINE-HEIGHT: 115%; FONT-FAMILY: 'sans-serif'"> of Bahawalpur, Pakistan</span></p></td></tr></tbody></table></div></blockquote></td></tr></tbody></table></blockquote><br><br><span title="neteasefooter"><span id="netease_mail_footer"></span></span>