Lowdin population analysis

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2:32:27 PM PDT - Fri, Oct 7th 2011
Hi,
  According to the manual, constrained DFT uses Lowdin populations by default (Mulliken not recommended). I would like to set up a calculation by taking converged MOs as a guess, then running CDFT with a cluster of atomic charges constrained to the value in the original calculation (just as a check, to ensure the same or similar wavefunction is produced). To do this, I guess I'd need the Lowdin charges for the original WF. Is there a database key/value pair that can be set to produce Lowdin population analysis, and if so what is it?

Thanks.

  • Bert Forum:Admin, Forum:Mod, NWChemDeveloper, bureaucrat, sysop
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10:03:07 AM PDT - Mon, Oct 10th 2011
Chris,

How counter intuitive it may sound, but adding the keyword "mulliken" to the dft block should print out both the Mulliken and Lowdin charges.

Bert


Quote:Cchang Oct 7th 10:32 pm
Hi,
  According to the manual, constrained DFT uses Lowdin populations by default (Mulliken not recommended). I would like to set up a calculation by taking converged MOs as a guess, then running CDFT with a cluster of atomic charges constrained to the value in the original calculation (just as a check, to ensure the same or similar wavefunction is produced). To do this, I guess I'd need the Lowdin charges for the original WF. Is there a database key/value pair that can be set to produce Lowdin population analysis, and if so what is it?

Thanks.

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12:03:09 PM PDT - Mon, Oct 10th 2011
Thanks Bert!
  Cheers,  Chris

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12:59:20 PM PST - Fri, Dec 23rd 2011
Not seeing Lowdin charges
Bert,

I tried adding "mulliken" in both a separate properties section, and in the dft block as you suggested; however, I'm not seeing anything labeled as "Lowdin" or anything else that would suggest an alternative charge model. What should I be looking for? NWChem 6.0 on Hopper @ NERSC.

Thanks,

Chris

  • Niri Forum:Admin, Forum:Mod, NWChemDeveloper, bureaucrat, sysop
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3:21:29 PM PST - Tue, Dec 27th 2011
Hi Chris,

Try the following:

dft
 mulliken

 ...
end
task dft

this will print out Mulliken and Lowdin sections in the output. Let me know if it doesn't work.

Best,
-Niri

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11:05:09 AM PST - Tue, Jan 3rd 2012
Hi Niri,
What keyword would be good to search on to find the Lowdin section? With the MO output, the log files are quite long.

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8:55:02 AM PST - Wed, Jan 4th 2012
Niri--Never mind, the analysis output contained the Lowdin data this time, and the log file was much shorter than it has been. Curious.

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2:30:12 AM PDT - Thu, Aug 30th 2012
Quote:Cchang Jan 4th 9:55 am
Niri--Never mind, the analysis output contained the Lowdin data this time, and the log file was much shorter than it has been. Curious.


Dear NWCHEM users,
I did the Lowdin and Mulliken population analysis to get partial charges for QM atoms in a QMMM simulation. But, results seems strange to me because, for example, for an O atom it results in 8.43 while the ESP analysis results in -0.64 (that looks reasonable). Is there any one who can help me to extract the real partial charges out of these numbers?

Best,
Hassan.

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7:45:36 PM PDT - Sun, Oct 14th 2012
Quote:Niri Dec 27th 4:21 pm
Hi Chris,

Try the following:

dft
 mulliken

 ...
end
task dft

this will print out Mulliken and Lowdin sections in the output. Let me know if it doesn't work.

Best,
-Niri


Thanks for the post. I did this along with / separately

dft
cdft 1 x charge 0.0 pop lowdin
....
end
task dft

but had no luck in getting the Lowdin charges with NWCHEM 6.1 @ hopper.nersc

Can some one please enlighten me with the proper keyword? Thanks in advance.
Edited On 7:58:36 PM PDT - Sun, Oct 14th 2012 by Himadride

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11:55:13 AM PDT - Mon, Oct 15th 2012
Himadride,
The input below is an example for how to calculate the Lowdin population analysis.

start n4
geometry
N -0.08327803 -0.57614137 -0.00048040
N 0.17646529 -1.65378010 0.00040716
N 0.44621621 1.56364198 0.00224466
N -0.53940347 0.66627949 -0.00217143
end
basis
* library 6-31g*
end
dft
odft
xc b3lyp
mult 3
cdft 1 2 charge 1.0
cdft 3 4 charge -1.0
mulliken
end

task dft

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12:16:59 PM PDT - Mon, Oct 15th 2012
Thanks for the reply. But it still does not work. Is there any other work around ? Thanks in advance.
Edited On 12:24:18 PM PDT - Mon, Oct 15th 2012 by Himadride

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1:56:30 PM PDT - Mon, Oct 15th 2012
I have just tried it with both the 6.1 and 6.1.1 default binaries on hopper and it works for me.

apra/cdft> egrep wdin cdft.out.2325240.sdb 
    Total Density - Lowdin Population Analysis

     Spin Density - Lowdin Population Analysis

Quote:Himadride Oct 15th 12:16 pm
Thanks for the reply. But it still does not work. Is there any other work around ? Thanks in advance.

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11:11:36 PM PDT - Wed, Oct 17th 2012
Thank you for the reply. It definitely works with the closed shell systems. My system is open shell and I use RODFT module accompanied by cgmin solver. Can you please let me know about it, whether with RODFT open shell systems too similar keywords are valid? Thanks in advance.

  • Bert Forum:Admin, Forum:Mod, NWChemDeveloper, bureaucrat, sysop
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12:16:41 AM PDT - Thu, Oct 18th 2012
This is a feature that has not been implemented in the RODFT yet. This will be made available in our next release.

Bert

Quote:Himadride Oct 18th 7:11 am
Thank you for the reply. It definitely works with the closed shell systems. My system is open shell and I use RODFT module accompanied by cgmin solver. Can you please let me know about it, whether with RODFT open shell systems too similar keywords are valid? Thanks in advance.


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