Dear sir,<br><br>I apologize for my pool understanding of your mails concerning my problems of convergence for SCF.<br><br>Because I am not strong enough with the theory background, I am not sensitive with what you said before. Now, you tell me how to overcome the problems so detail. I think I really benefit from your mail this time.<br>
<br>By the way, my understanding on quantum mechanism or quantum chemistry is not good enough. My purpose is to use the code to solve the problem and make better understanding with the materials we focus on. Do you think the theory background is really important for all the users of scientific code, even for researchers in chemical engineering or applied physics? <br>
<br>thank you for your time. <br><br>vega<br><br><div class="gmail_quote">On Sun, Mar 1, 2009 at 9:17 PM, Eyvaz Isaev <span dir="ltr"><<a href="mailto:eyvaz_isaev@yahoo.com">eyvaz_isaev@yahoo.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Dear Vega,<br>
<br>
It was explained many times in the case of surface calculations (you introduced a defect also) you should consider your system as metallic due to induced states (by dangling bonds or defects).<br>
So, make your system metallic turning on occupations="smearing" and related keywords.<br>
<br>
Of course, the use of mixing_mode='local-TF' and mixing_beta=0.1 is preferable in your calculations as your system is highly inhomogeneous.<br>
<br>
Bests,<br>
Eyvaz.<br>
<br>
-------------------------------------------------------------------<br>
Prof. Eyvaz Isaev,<br>
Theoretical Physics Department, Moscow State Institute of Steel & Alloys, Russia,<br>
Department of Physics, Chemistry, and Biology (IFM), Linkoping University, Sweden<br>
Condensed Matter Theory Group, Uppsala University, Sweden<br>
<a href="mailto:Eyvaz.Isaev@fysik.uu.se">Eyvaz.Isaev@fysik.uu.se</a>, <a href="mailto:isaev@ifm.liu.se">isaev@ifm.liu.se</a>, <a href="mailto:eyvaz_isaev@yahoo.com">eyvaz_isaev@yahoo.com</a><br>
<br>
<br>
--- On Sun, 3/1/09, vega lew <<a href="mailto:quantumdft@gmail.com">quantumdft@gmail.com</a>> wrote:<br>
<br>
> From: vega lew <<a href="mailto:quantumdft@gmail.com">quantumdft@gmail.com</a>><br>
> Subject: [Pw_forum] converge problem in calculating the vacancy on TiO2 surfaces<br>
> To: "PWSCF Forum" <<a href="mailto:pw_forum@pwscf.org">pw_forum@pwscf.org</a>><br>
> Date: Sunday, March 1, 2009, 11:19 AM<br>
<div><div></div><div class="Wj3C7c">> Dear all,<br>
><br>
> I am planning to calculate the Oxygen vacancy properties of<br>
> TiO2 surfaces.<br>
> The calculation for the ideal surfaces are quite normal and<br>
> the results are<br>
> in line with the one that literature reported. But, when I<br>
> tried to<br>
> calculate the anatase 101 surface with an Oxygen vacancy<br>
> (O2c was removed<br>
> directly from the stoichiometric Anatase 101as described in<br>
> J. Phys. Chem. C<br>
> 2007, 111, 16397-16404, I encounter the problem of<br>
> convergence for SCF<br>
> cycle. I tried to add 20% more empty band to the system<br>
> the problem still<br>
> laid in. How could I overcome the problem?<br>
><br>
> my input file was attached at the bottom of the mail<br>
><br>
> thank you for reading. Any hints will be appreciated.<br>
><br>
> vega<br>
><br>
><br>
><br>
> &CONTROL<br>
><br>
> title = 'Anatase 101 1x3'<br>
> ,<br>
> calculation = 'relax'<br>
> ,<br>
> restart_mode = 'from_scratch'<br>
> ,<br>
> outdir = '/tmp/' ,<br>
> wfcdir = '/tmp/'<br>
> ,<br>
> pseudo_dir =<br>
> '/home/vega/espresso-4.0/pseudo/' ,<br>
> prefix = 'Anatase 101 1x3'<br>
> ,<br>
> disk_io = 'none'<br>
> ,<br>
> nstep = 1000<br>
> ,<br>
> /<br>
><br>
> &SYSTEM<br>
><br>
> ibrav =<br>
> 8,<br>
> celldm(1) =19.3269,<br>
> celldm(2) = 1.1094,<br>
> celldm(3) = 1.7450,<br>
> nat =<br>
> 71,<br>
> ntyp =<br>
> 2,<br>
> nosym = .true.<br>
> ,<br>
> ecutwfc = 30,<br>
> ecutrho = 300,<br>
> /<br>
><br>
> &ELECTRONS<br>
><br>
><br>
><br>
> /<br>
><br>
> &IONS<br>
><br>
> ion_dynamics = 'bfgs'<br>
> ,<br>
> /<br>
><br>
> ATOMIC_SPECIES<br>
><br>
> Ti 47.86700<br>
> Ti.pw91-sp-van_ak.UPF<br>
> O 15.99940<br>
> O.pw91-van_ak.UPF<br>
> ATOMIC_POSITIONS<br>
> crystal<br>
> Ti 0.79001 0.05515 0.04075 0 0 0<br>
> Ti 0.92677 0.05515 0.23765 1 1 1<br>
> Ti 0.29001 0.22181 0.04075 0 0 0<br>
> Ti 0.42677 0.22181 0.23765 1 1 1<br>
> Ti 0.57420 0.22181 0.08998 0 0 0<br>
> Ti 0.71096 0.22181 0.28687 1 1 1<br>
> Ti 0.07420 0.05515 0.08998 0 0 0<br>
> Ti 0.21096 0.05515 0.28687 1 1 1<br>
> O 0.61134 0.05515 0.08150 0 0 0<br>
> O 0.74810 0.05515 0.27840 1 1 1<br>
> O 0.11134 0.22181 0.08150 0 0 0<br>
> O 0.24810 0.22181 0.27840 1 1 1<br>
> O 0.39553 0.22181 0.13073 0 0 0<br>
> O 0.53229 0.22181 0.32763 1 1 1<br>
> O 0.89553 0.05515 0.13073 0 0 0<br>
> O 0.03229 0.05515 0.32763 1 1 1<br>
> O 0.25286 0.05515 0.04922 0 0 0<br>
> O 0.38962 0.05515 0.24612 1 1 1<br>
> O 0.75286 0.22181 0.04922 0 0 0<br>
> O 0.88962 0.22181 0.24612 1 1 1<br>
> O 0.46867 0.22181 0.00000 0 0 0<br>
> O 0.60543 0.22181 0.19690 1 1 1<br>
> O 0.96867 0.05515 0.00000 0 0 0<br>
> O 0.10543 0.05515 0.19690 1 1 1<br>
> Ti 0.79001 0.38848 0.04075 0 0 0<br>
> Ti 0.92677 0.38848 0.23765 1 1 1<br>
> Ti 0.29001 0.55515 0.04075 0 0 0<br>
> Ti 0.42677 0.55515 0.23765 1 1 1<br>
> Ti 0.57420 0.55515 0.08998 0 0 0<br>
> Ti 0.71096 0.55515 0.28687 1 1 1<br>
> Ti 0.07420 0.38848 0.08998 0 0 0<br>
> Ti 0.21096 0.38848 0.28687 1 1 1<br>
> O 0.61134 0.38848 0.08150 0 0 0<br>
> O 0.74810 0.38848 0.27840 1 1 1<br>
> O 0.11134 0.55515 0.08150 0 0 0<br>
> O 0.24810 0.55515 0.27840 1 1 1<br>
> O 0.39553 0.55515 0.13073 0 0 0<br>
> #O 0.53229 0.55515 0.32763 1 1 1<br>
> O 0.89553 0.38848 0.13073 0 0 0<br>
> O 0.03229 0.38848 0.32763 1 1 1<br>
> O 0.25286 0.38848 0.04922 0 0 0<br>
> O 0.38962 0.38848 0.24612 1 1 1<br>
> O 0.75286 0.55515 0.04922 0 0 0<br>
> O 0.88962 0.55515 0.24612 1 1 1<br>
> O 0.46867 0.55515 0.00000 0 0 0<br>
> O 0.60543 0.55515 0.19690 1 1 1<br>
> O 0.96867 0.38848 0.00000 0 0 0<br>
> O 0.10543 0.38848 0.19690 1 1 1<br>
> Ti 0.79001 0.72181 0.04075 0 0 0<br>
> Ti 0.92677 0.72181 0.23765 1 1 1<br>
> Ti 0.29001 0.88848 0.04075 0 0 0<br>
> Ti 0.42677 0.88848 0.23765 1 1 1<br>
> Ti 0.57420 0.88848 0.08998 0 0 0<br>
> Ti 0.71096 0.88848 0.28687 1 1 1<br>
> Ti 0.07420 0.72181 0.08998 0 0 0<br>
> Ti 0.21096 0.72181 0.28687 1 1 1<br>
> O 0.61134 0.72181 0.08150 0 0 0<br>
> O 0.74810 0.72181 0.27840 1 1 1<br>
> O 0.11134 0.88848 0.08150 0 0 0<br>
> O 0.24810 0.88848 0.27840 1 1 1<br>
> O 0.39553 0.88848 0.13073 0 0 0<br>
> O 0.53229 0.88848 0.32763 1 1 1<br>
> O 0.89553 0.72181 0.13073 0 0 0<br>
> O 0.03229 0.72181 0.32763 1 1 1<br>
> O 0.25286 0.72181 0.04922 0 0 0<br>
> O 0.38962 0.72181 0.24612 1 1 1<br>
> O 0.75286 0.88848 0.04922 0 0 0<br>
> O 0.88962 0.88848 0.24612 1 1 1<br>
> O 0.46867 0.88848 0.00000 0 0 0<br>
> O 0.60543 0.88848 0.19690 1 1 1<br>
> O 0.96867 0.72181 0.00000 0 0 0<br>
> O 0.10543 0.72181 0.19690 1 1 1<br>
> K_POINTS gamma<br>
><br>
> --<br>
> ==================================================================================<br>
> Vega Lew ( weijia liu)<br>
> PH.D Candidate in Chemical Engineering<br>
> State Key Laboratory of Materials-oriented Chemical<br>
> Engineering<br>
> College of Chemistry and Chemical Engineering<br>
> Nanjing University of Technology, 210009, Nanjing, Jiangsu,<br>
> China<br>
> ******************************************************************************************************************<br>
> Email: <a href="mailto:vegalew@gmail.com">vegalew@gmail.com</a><br>
> Office: Room A705, Technical Innovation Building, Xinmofan<br>
> Road 5#, Nanjing,<br>
> Jiangsu, China<br>
> ******************************************************************************************************************<br>
</div></div><div><div></div><div class="Wj3C7c">> _______________________________________________<br>
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</div></div></blockquote></div><br><br clear="all"><br>-- <br>==================================================================================<br>Vega Lew ( weijia liu)<br>PH.D Candidate in Chemical Engineering<br>State Key Laboratory of Materials-oriented Chemical Engineering<br>
College of Chemistry and Chemical Engineering<br>Nanjing University of Technology, 210009, Nanjing, Jiangsu, China<br>******************************************************************************************************************<br>
Email: <a href="mailto:vegalew@gmail.com">vegalew@gmail.com</a><br>Office: Room A705, Technical Innovation Building, Xinmofan Road 5#, Nanjing, Jiangsu, China <br>****************************************************************************************************************** <br>