No subject
Tue Jul 10 14:20:16 CEST 2007
Gamma (0,0,0)
N (0, 1/2, 0)
X (0,0,1/2)
P (1/4,1/4,1/4)
Z (1/2,1/2,-1/2)
I don't recall getting any errors or strange results when choosing paths bet=
ween these points. You should search for this thesis as a good reference fo=
r titania.
Luke
----- Original Message -----=20
From: lan haiping=20
To: pw_forum at pwscf.org=20
Sent: Monday, October 23, 2006 12:38 AM
Subject: Re: [Pw_forum] question about bands calculation
Dear Luke,
thanks for your reply. my structure is anatase titania.
Actually, i set the k-point paths according to high symmetry lines such as=
\Gamma[0,0,0] to Z [0,0,0.5] , Z to Q[0,0.5,0.5] etc.
Is it right ?
Regards,
hai-ping
=20
On 10/22/06, lukethulin at netscape.net <lukethulin at netscape.net> wrote:=20
Hai-ping,
I don't think you're going about a band structure calculation correctly.=
The scf calculation should only use automatic k-point selection of (4,4,4)=
or something like that. The following nscf calculation needs you to input=20=
k-paths along high symmetry lines that vary by crystal structure. What form=
of titania are you modeling, anatase, rutile?=20
Luke
----- Original Message -----=20
From: lan haiping=20
To: pw_forum=20
Sent: Saturday, October 21, 2006 2:31 PM
Subject: [Pw_forum] question about bands calculation
=20
Hi!
i have a question about bands calculation .
Just after finished a 'scf' calculation for tio2, i performed a serie=
s (about 5) 'nscf' calculations with different k-grid paths. Except k-grid=
path, all settings are the same for these series ' nscf ' calculation. =20
In some nscf-output, the values of "Highest occupied level and lowest=
unoccuped level" are found. But these values are not found in the other=20=
nscf-output . I donot know what the reasons are related to . Morever, i also=
came to a calculation failed with complains "Too many eigenvalues are not c=
onverged". =20
Regards,
hai-ping
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<DIV><FONT face=3DArial size=3D2>hai-ping,</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>From a 2003 thesis by Giovanni Cangiani, bu=
t=20
obviously there are other sources:</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Gamma (0,0,0)</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>N (0, 1/2, 0)</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>X (0,0,1/2)</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>P (1/4,1/4,1/4)</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Z (1/2,1/2,-1/2)</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>I don't recall getting any errors or strang=
e=20
results when choosing paths between these points. You should search fo=
r=20
this thesis as a good reference for titania.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Luke</FONT></DIV>
<BLOCKQUOTE style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5=
px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black=
"><B>From:</B>=20
<A title=3Dlanhaiping at gmail.com href=3D"mailto:lanhaiping at gmail.com">lan=20
haiping</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>To:</B> <A title=3Dpw_forum at pwscf.org =20=
href=3D"mailto:pw_forum at pwscf.org">pw_forum at pwscf.org</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Monday, October 23, 2006 12:3=
8=20
AM</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> Re: [Pw_forum] question ab=
out=20
bands calculation</DIV>
<DIV><BR></DIV>
<DIV>Dear Luke,</DIV>
<DIV>thanks for your reply. my structure is anatase titania.</DIV>
<DIV>Actually, i set the k-point paths according to high symmetry lines su=
ch=20
as \Gamma[0,0,0] to Z [0,0,0.5] , Z to Q[0,0.5,0.5] etc.</DIV>
<DIV>Is it right ?</DIV>
<DIV> </DIV>
<DIV>Regards,</DIV>
<DIV>hai-ping<BR><BR> </DIV>
<DIV><SPAN class=3Dgmail_quote>On 10/22/06, <B class=3Dgmail_sendername><A=
href=3D"mailto:lukethulin at netscape.net">lukethulin at netscape.net</A></B>=
<<A href=3D"mailto:lukethulin at netscape.net">lukethulin at netscape.net<=
/A>> wrote:=20
</SPAN>
<BLOCKQUOTE class=3Dgmail_quote style=3D"PADDING-LEFT: 1ex; MARGIN: 0p=
x 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">
<DIV bgcolor=3D"#ffffff">
<DIV><FONT face=3DArial size=3D2>Hai-ping,</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>I don't think you're going about a band=
=20
structure calculation correctly. The scf calculation should only u=
se=20
automatic k-point selection of (4,4,4) or something like that. The=
=20
following nscf calculation needs you to input k-paths along high symmetr=
y=20
lines that vary by crystal structure. What form of titania are you=
=20
modeling, anatase, rutile? </FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Luke</FONT></DIV>
<DIV><SPAN class=3De id=3Dq_10e70716ed52f088_1>
<BLOCKQUOTE dir=3Dltr style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5=
px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial"><B>From:</B> <A =20=
title=3Dlanhaiping at gmail.com onclick=3D"return top.js.OpenExt=
Link(window,event,this)" href=3D"mailto:lanhaiping at gmail.com" target=
=3D_blank>lan haiping</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>To:</B> <A title=3Dpw_forum at pwscf.o=
rg onclick=3D"return top.js.OpenExtLink(window,event,this)" =20=
href=3D"mailto:pw_forum at pwscf.org" target=3D_blank>pw_forum</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Saturday, October 21, 200=
6 2:31=20
PM</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> [Pw_forum] question ab=
out=20
bands calculation</DIV>
<DIV><BR> </DIV>
<DIV>Hi!</DIV>
<DIV> </DIV>
<DIV> i have a question about bands calculation .</DIV>
<DIV> Just after finished a '<STRONG>scf</STRONG>' calculati=
on=20
for tio2, i performed a series (about 5) =20
'<STRONG>nscf</STRONG>' calculations with different k-grid=20
paths. Except k-grid path, all settings are the same for these series=20=
'=20
nscf ' calculation. </DIV>
<DIV>In some nscf-output, the values of "Highest occupied level=20=
and=20
lowest unoccuped level" are found. But these values=20=
are=20
not found in the other nscf-output . I donot know what the reasons are=
=20
related to . Morever, i also came to a calculation failed with complai=
ns=20
"Too many eigenvalues are not converged". </DIV>
<DIV> </DIV>
<DIV>Regards,</DIV>
<DIV>hai-ping</DIV>
<DIV> </DIV>
<DIV> </DIV></BLOCKQUOTE></SPAN></DIV></DIV></BLOCKQUOTE></DIV><B=
R></BLOCKQUOTE></BODY></HTML>
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