<html><head></head><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:13px"><div id="yui_3_16_0_ym19_1_1503075866104_206797">Dear Professor Peter Blaha, Tran and Wien2k users,</div><div><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1503075866104_206774">I have computed the energy gap for Cu2O by using GGA, mBJ, and GGA+U, I got same energy gap of 1 eV.</div><div dir="ltr" id="yui_3_16_0_ym19_1_1503075866104_206715">In principle by using mBJ, the energy gap should be increased close to expermimental value around 2 eV.</div><div dir="ltr" id="yui_3_16_0_ym19_1_1503075866104_206714">Why mBJ is giving same value as GGA and it is not improved? even I tried GGA+U and the same problem and no thing was changed for all approximations.</div><div dir="ltr" id="yui_3_16_0_ym19_1_1503075866104_206714"><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1503075866104_206714">I would be thankful for your suggestion and answer to solve the problem.</div><div dir="ltr" id="yui_3_16_0_ym19_1_1503075866104_206714"><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1503075866104_206714">Sincerely yours,</div><div dir="ltr" id="yui_3_16_0_ym19_1_1503075866104_206714"><br></div><div dir="ltr" id="yui_3_16_0_ym19_1_1503075866104_206714">Halim Said</div></div></body></html>