<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=us-ascii">
<META content="MSHTML 6.00.2900.5583" name=GENERATOR><LINK
href="BLOCKQUOTE{margin-Top: 0px; margin-Bottom: 0px; margin-Left: 2em}"
rel=stylesheet></HEAD>
<BODY style="FONT-SIZE: 10pt; FONT-FAMILY: verdana">
<DIV>Dear Pwscf users, </DIV>
<DIV> </DIV>
<DIV> Recently I found an effective way on input defining a
based-centered monoclinic cell.</DIV>
<DIV> </DIV>
<DIV>In fact, we could change the setting (ibrav=13) in the
flib/latgen.f90 from </DIV>
<DIV>
<DIV><EM><FONT
color=#ff0000> sen = sqrt( 1.d0 - celldm(4) ** 2 )</FONT></EM></DIV>
<DIV><EM><FONT
color=#ff0000> a1(1) = 0.5 * celldm(1)</FONT></EM></DIV>
<DIV><EM><FONT
color=#ff0000> a1(3) =-a1(1) * celldm(3)</FONT></EM></DIV>
<DIV><EM><FONT
color=#ff0000> a2(1) = celldm(1) * celldm(2) * celldm(4)</FONT></EM></DIV>
<DIV><EM><FONT
color=#ff0000> a2(2) = celldm(1) * celldm(2) * sen</FONT></EM></DIV>
<DIV><EM><FONT
color=#ff0000> a3(1) = a1(1)</FONT></EM></DIV>
<DIV><EM><FONT
color=#ff0000> a3(3) =-a1(3)</FONT></EM></DIV></DIV>
<DIV> </DIV>
<DIV>to </DIV>
<DIV> </DIV>
<DIV>
<DIV><FONT
color=#0000ff><FONT> <EM> sen = sqrt( 1.d0 - celldm(4) ** 2 )</EM></FONT></FONT></DIV>
<DIV><EM><FONT
color=#0000ff> a1(2) = 0.5 * celldm(1)</FONT></EM></DIV>
<DIV><EM><FONT
color=#0000ff> a1(3) =-0.5 * celldm(2) * celldm(1)</FONT></EM></DIV>
<DIV><EM><FONT
color=#0000ff> a2(2) = 0.5 * celldm(1)</FONT></EM></DIV>
<DIV><EM><FONT
color=#0000ff> a2(3) = 0.5 * celldm(2) * celldm(1)</FONT></EM></DIV>
<DIV><EM><FONT
color=#0000ff> a3(1) = celldm(3) * sen * celldm(1)</FONT></EM></DIV>
<DIV><EM><FONT
color=#0000ff> a3(2) = celldm(3) * celldm(4) * celldm(1)</FONT></EM></DIV></DIV>
<DIV> </DIV>
<DIV>which corresponding with the defining form in the MS. </DIV>
<DIV> </DIV>
<DIV>I have tested it and found this way of defining could give us a right
structure.</DIV>
<DIV> </DIV>
<DIV>For some stuctures which have problems in input defining the cell, I think
we could resolve it in the same way </DIV>
<DIV>"change the defining form in latgen.f90 to a new one which
corresponding with that in the MS"</DIV>
<DIV> </DIV>
<DIV>Good Luck!</DIV>
<DIV> </DIV>
<DIV>Yinwei Li<FONT face=Verdana color=#c0c0c0 size=2>2009-</FONT></DIV>
<DIV><FONT face=Verdana color=#c0c0c0 size=2></FONT> </DIV>
<DIV><FONT face=Verdana color=#c0c0c0 size=2></FONT> </DIV>
<DIV><FONT face=Verdana color=#c0c0c0 size=2>Y03-07
body centered tetragonal </FONT></DIV><FONT face=Verdana size=2>
<HR style="WIDTH: 122px; HEIGHT: 2px" align=left SIZE=2>
<DIV><FONT face=Verdana color=#c0c0c0 size=2><SPAN>
<DIV> sen = sqrt( 1.d0 - celldm(4) ** 2 )</DIV>
<DIV> a1(1) = 0.5 * celldm(1)</DIV>
<DIV> a1(3) =-a1(1) * celldm(3)</DIV>
<DIV> a2(1) = celldm(1) * celldm(2) * celldm(4)</DIV>
<DIV> a2(2) = celldm(1) * celldm(2) * sen</DIV>
<DIV> a3(1) = a1(1)</DIV>
<DIV> a3(3) =-a1(3)</DIV>yinwei_li</SPAN>
</FONT></DIV></FONT></BODY></HTML>