<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:times new roman, new york, times, serif;font-size:18pt;color:#000000;"><DIV></DIV>
<DIV>Dear everyone:</DIV>
<DIV> </DIV>
<DIV>I have some questions about grid offsets.</DIV>
<DIV> </DIV>
<DIV>In our input file, the k-points are automatically generated with uniform grid, and the grid offsets are either set as 0 (no offset) or 1 (grid displaced by 1/2 step). But the problem is that we got different results with different offsets.</DIV>
<DIV> </DIV>
<DIV>For example, we tested the adsorption of one oxygen atom on three low-index Pt crystal planes, namely, Pt(100), Pt(110) and Pt(111). With grid shift (0 0 0), the adsorption energy of O on Pt(110) is slightly larger than on Pt(100), but much larger than on Pt(111). However, with grid shift (1 1 1), the order of adsorption energy is Pt(110)>Pt(111)>Pt(100). </DIV>
<DIV> </DIV>
<DIV>Which result is more reasonable?</DIV>
<DIV> </DIV>
<DIV>Best Regards & Merry Christmas,</DIV>
<DIV> </DIV>
<DIV>Fan Yang</DIV>
<DIV>*******************************************</DIV>
<DIV>Fan Yang</DIV>
<DIV>PH.D Candidate in Electrochemistry</DIV>
<DIV>College of Chemistry and Molecular Science</DIV>
<DIV>Wuhan University, <EM>430072</EM>, Hubei Province, China</DIV>
<DIV><EM>E-mail:shrek_826@yahoo.com.cn</EM></DIV>
<DIV>*******************************************</DIV>
<DIV></DIV><!-- cg6.c21.mail.cnh.yahoo.com compressed Fri Dec 4 01:42:05 PST 2009 --></div><br>
<hr size=1><a href="http://cn.rd.yahoo.com/mail_cn/tagline/card/*http://card.mail.cn.yahoo.com/"> 好玩贺卡等你发，邮箱贺卡全新上线！</a></body></html>