<html><head></head><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:16px"><div id="yui_3_16_0_ym19_1_1465572437698_16670">Dear all <br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1465572437698_16682">I am confuse a little bit about my structure .I built a multilayer of graphene .When I use ibrav=0 and define the lattice parameter I cannot visualize my structure with xcrysden , but when I add celldm(1)=1.5 , I can visualize the structure with xcrysden .I am asking if someone know what is the real problem of that. Thank for any help regarding my request.Please find below my input data.</div><div id="yui_3_16_0_ym19_1_1465572437698_17078" dir="ltr">Regards</div><div id="yui_3_16_0_ym19_1_1465572437698_17079" dir="ltr">Omar Faye<br></div></div></body></html>