<html><head></head><body><div style="color:#000; background-color:#fff; font-family:Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:13px"><div id="yui_3_16_0_ym19_1_1506668289579_2704">Dear QE users,</div><div id="yui_3_16_0_ym19_1_1506668289579_2575"><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1506668289579_2526">I apologize if the question seem trivial. I have searched the pw-forum archive for a solution but did not get any.</div><div dir="ltr" id="yui_3_16_0_ym19_1_1506668289579_2574"><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1506668289579_2573">I want to set up the input of a BCC material using ibrav= 0</div><div dir="ltr" id="yui_3_16_0_ym19_1_1506668289579_2560">When I set ibrav=3, the structure looks okay from xcrysden<br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1506668289579_2612">&SYSTEM<br id="yui_3_16_0_ym19_1_1506668289579_2632"> ibrav = 3,<br id="yui_3_16_0_ym19_1_1506668289579_2633"> celldm(1) = 6.475745143,<br id="yui_3_16_0_ym19_1_1506668289579_2634"> nat = 1,<br id="yui_3_16_0_ym19_1_1506668289579_2635"> ntyp = 1,<br id="yui_3_16_0_ym19_1_1506668289579_2636"><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1506668289579_2561"><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1506668289579_2525">But with ibav=0 and the CELL_PARAMETER card included, the structure looks different (not BCC).<br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1506668289579_2698">&SYSTEM<br id="yui_3_16_0_ym19_1_1506668289579_2774"> ibrav = 0,<br id="yui_3_16_0_ym19_1_1506668289579_2775"> celldm(1) = 6.475745143,<br id="yui_3_16_0_ym19_1_1506668289579_2776"> nat = 1,<br id="yui_3_16_0_ym19_1_1506668289579_2777"> ntyp = 1,<br id="yui_3_16_0_ym19_1_1506668289579_2778">.....</div><div dir="ltr" id="yui_3_16_0_ym19_1_1506668289579_2779">CELL_PARAMETERS<br id="yui_3_16_0_ym19_1_1506668289579_2824"> 0.500000 0.500000 0.500000<br id="yui_3_16_0_ym19_1_1506668289579_2825"> -0.500000 0.500000 0.500000<br id="yui_3_16_0_ym19_1_1506668289579_2826"> -0.500000 -0.500000 0.500000<br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1506668289579_2524"><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1506668289579_2894"><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1506668289579_2895">However, I noticed that with ibrav=0 and</div><div dir="ltr" id="yui_3_16_0_ym19_1_1506668289579_2915">CELL_PARAMETERS<br id="yui_3_16_0_ym19_1_1506668289579_2933">1.0 0.0 0.0<br id="yui_3_16_0_ym19_1_1506668289579_2934">0.0 1.0 0.0<br id="yui_3_16_0_ym19_1_1506668289579_2935">0.0 0.0 1.0<br id="yui_3_16_0_ym19_1_1506668289579_2936">using the vectors of a simple cubic material and ntyp =2 at atomic postions 0,0,0 and 1/2,1/2,1/2, the structure is seen as BCC from xcrysden. <br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1506668289579_3017"><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1506668289579_3019">I desire to use ibrav=0 and the lattice vectors of a BCC crystal. <br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1506668289579_3319">I will sincerely appreciate any comment that can help me proceed with my calculation.</div><div dir="ltr" id="yui_3_16_0_ym19_1_1506668289579_3099"><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1506668289579_3100">Thank you.</div><div dir="ltr" id="yui_3_16_0_ym19_1_1506668289579_3108"><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1506668289579_3109">Jolayemi Omamuyovwi RIta</div><div dir="ltr" id="yui_3_16_0_ym19_1_1506668289579_3227">Research Student<br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1506668289579_3228">University of Benin</div><div dir="ltr" id="yui_3_16_0_ym19_1_1506668289579_3229">Nigeria.<br></div></div></body></html>