LDA+U calculation using Exciting

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wumindt2
Date: 03 May 2011 02:01
Number of posts: 16

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Summary:

U value was not readed by the code

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LDA+U calculation using Exciting

wumindt2 03 May 2011 02:01

Dear All,

I met a problem with the LDA+U calculation, using the latest version of exciting-helium.
After the U value was added, the ground state of the material was not changed at all.
I also check the density of states and it's exact the same as that when the U value was not
employed. I think it mightbe the case that the U value was not readed by the code at all.
Can someone tell me what's the problem of it? Any solution? Thanks for any help!

Below is my input for the ground state calculation, the orbital on which i want to add U parameter is 4f electron
of Ce atom.

<input xsi:noNamespaceSchemaLocation="/usr/local/exciting-helium/xml/excitinginput.xsd"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsltpath="/usr/local/exciting-helium/xml/">
 
  <title>CeO2</title>
 
  <structure speciespath="./">
    <crystal scale="10.225254" >
      <basevect>1.00000 0.00000 0.00000</basevect>
      <basevect>0.00000 1.00000 0.00000</basevect>
      <basevect>0.00000 0.000000 1.00000</basevect>
    </crystal>
    <species speciesfile="Ce_APWloLegacy.xml">
        <atom coord="  0.00000   0.00000   0.00000  " bfcmt="0.0 0.0 0.0" />
        <atom coord="  0.00000   0.50000   0.50000  " bfcmt="0.0 0.0 0.0" />
        <atom coord="  0.50000   0.00000   0.50000  " bfcmt="0.0 0.0 0.0" />
        <atom coord="  0.50000   0.50000   0.00000  " bfcmt="0.0 0.0 0.0" />
           <LDAplusU J="0.7d0" U="7.0d0" l="3" />
           <LDAplusU J="0.7d0" U="7.0d0" l="3"  />
           <LDAplusU J="0.7d0" U="7.0d0" l="3"  />
           <LDAplusU J="0.7d0" U="7.0d0" l="3" />
</species>
    <species speciesfile="O_APWloLegacy_BSE.xml">
            <atom coord="  0.25000   0.25000   0.25000    " bfcmt="0.0 0.0 0.0" />
            <atom coord="  0.75000   0.75000   0.25000    " bfcmt="0.0 0.0 0.0" />
            <atom coord="  0.75000   0.25000   0.75000    " bfcmt="0.0 0.0 0.0" />
            <atom coord="  0.25000   0.75000   0.75000    " bfcmt="0.0 0.0 0.0" />
            <atom coord="  0.25000   0.25000   0.75000    " bfcmt="0.0 0.0 0.0" />
            <atom coord="  0.75000   0.75000   0.75000    " bfcmt="0.0 0.0 0.0" />
            <atom coord="  0.75000   0.25000   0.25000    " bfcmt="0.0 0.0 0.0" />
            <atom coord="  0.25000   0.75000   0.25000    " bfcmt="0.0 0.0 0.0" />
</species>
  </structure>
 
  <groundstate   lradstep="2" beta0="0.2d0" deband="0.01d0" lmaxvr="8"  gmaxvr="16" ngridk="2 2 2" vkloff="0.05 0.15 0.25">
  </groundstate>
   <properties>
       <dos winddos= "-1.0 1.0"  />
   </properties>
</input>

Min WU
2011-5-2

Last edited on 10 May 2011 07:40 by chmberg Show more

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Unfold LDA+U calculation using Exciting by

wumindt2, 03 May 2011 02:01

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testuser (guest) 03 May 2011 08:54

LDAplusU gets only switched on by the ldapu attribute of the groundstate. I realize that the documentation does not mention this. I hope this helps.

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testuser (guest), 03 May 2011 08:54

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wumindt2 09 May 2011 04:26

Then which option of ldapu attribute was recommended? "FullyLocalisedLimit", "AroundMeanField" or "FFL-AMF-interpolation"? What's the difference?

Thanks!

Min Wu

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wumindt2, 09 May 2011 04:26

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wumindt2 09 May 2011 19:55

I added the ldapu attribute, but the energy still hasn't changed at all.
It seems that the U parameter was not read by the code.
Any help?
Thanks!

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wumindt2, 09 May 2011 19:55

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Re: LDA+U calculation using Exciting

chmberg 03 May 2011 09:06

There is only one LDAplusU element expected in the species element. I actually wonder why the parser did not complain. What version are you using?

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chmberg, 03 May 2011 09:06

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Re: LDA+U calculation using Exciting

wumindt2 09 May 2011 04:23

Do you mean i just need one line of "<LDAplusU J="0.7d0" U="7.0d0" l="3" />" ?
Whatif i need to use different U values for unequivalent atoms of the same species?
The version i'm using is exciting-helium.

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wumindt2, 09 May 2011 04:23

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Re: LDA+U calculation using Exciting

chmberg 09 May 2011 07:47

Nothing prevents you from using a separate species with the same species file, I think.

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chmberg, 09 May 2011 07:47

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Re: LDA+U calculation using Exciting

wumindt2 09 May 2011 16:04

Do you mean in a same species we just specify the U value one time for the orbitals?

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wumindt2, 09 May 2011 16:04

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Re: LDA+U calculation using Exciting

chmberg 10 May 2011 07:39

I mean like this:

<species speciesfile="Ce_APWloLegacy.xml">
  <atom coord=" 0.00000 0.00000 0.00000 " bfcmt="0.0 0.0 0.0" /> 
  <atom coord=" 0.00000 0.50000 0.50000 " bfcmt="0.0 0.0 0.0" />
  <LDAplusU J="0.7d0" U="7.0d0" l="3" />
</species>
<species speciesfile="Ce_APWloLegacy.xml">
  <atom coord=" 0.50000 0.00000 0.50000 " bfcmt="0.0 0.0 0.0" />
  <atom coord=" 0.50000 0.50000 0.00000 " bfcmt="0.0 0.0 0.0" />
  <LDAplusU J="0.7d0" U="7.5d0" l="3" />
</species>

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Unfold Re: LDA+U calculation using Exciting by

chmberg, 10 May 2011 07:39

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Min Wu (guest) 18 May 2011 14:18

I tried, but the energy levels still didn't change.
Anyone have successfully done the calculation with hubbard U?
Thanks for any help.

Min Wu

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Min Wu (guest), 18 May 2011 14:18

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chmberg 19 May 2011 09:27

Unfortunately, I don't know this well enough. But do post an example you expect to work. I might give it a try to find out whats going on.

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chmberg, 19 May 2011 09:27

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Min Wu (guest) 20 May 2011 23:02

You can use my first post as an example.

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Min Wu (guest), 20 May 2011 23:02

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Min Wu (guest) 03 Jun 2011 21:44

Is there anyone have successfully done calculation with Hubbard U using Exciting code ?

Min Wu

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Min Wu (guest), 03 Jun 2011 21:44

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chmberg 06 Jun 2011 12:09

As we ported the exciting code to the new input, we did a few tests. But i don't know of anybody who seriously tried to use it except for you maybe. Sorry for being of so little help.

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chmberg, 06 Jun 2011 12:09

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LDA+U

stephans 06 Jun 2011 13:18

Dear all,

we are sorry that the LDA+U feature was not properly connected to the main code in this release.
Currently we are fixing this problem, and a new release is approaching.

Cheers,
Stephan

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stephans, 06 Jun 2011 13:18

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LDA+U fixed

stephans 07 Jun 2011 10:22

Dear all,

the LDA+U feature should now be working properly.
Meanwhile (until the next release) you can download a bugfix-version of the code from this location

https://github.com/exciting/exciting/tarball/30556d66b0e06e37a8c65249d5258affba4ebde6

Be aware that the libbzint library is not included in this tarfile.

Cheers,
Stephan

Last edited on 07 Jun 2011 11:40 by stephans Show more

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Unfold LDA+U fixed by

stephans, 07 Jun 2011 10:22

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