Re: [cclib-users] orbital occupation numbers

[Karol L. <kar...@gm...>]

I created an issue for this:
https://github.com/cclib/cclib/issues/143

On Thu, Oct 23, 2014 at 12:31 PM, Karol Langner <kar...@gm...>
wrote:

> Axel,
>
> The terminology seems to be a little tricky. To be specific, the NO
> coefficients that we currently parse (for Gaussian) are those that define
> the natural orbital as an eigenvector of the diagonalized density matrix.
>
> Here is an example of the output from out unit tests:
>
> https://github.com/cclib/cclib/blob/master/data/Gaussian/basicGaussian09/water_cis.log#L578
>
> The eigenvalues printed there, I think, are the occupoation numbers you
> need (the population in each orbital), although in that particular case
> some are negative (maybe because the basis set is so small?). Anyway, we
> don't parse them, but we could of course, if that will be useful for you.
>
> Cheers,
> Karol
>
> P.S. A new release of cclib (1.3) is coming out soon. Which version are
> you using? In any case, this will not make it into 1.3, so you will need to
> use the dev version from github.
>
>
> On Thu, Oct 23, 2014 at 12:07 PM, Axel Schild <axe...@go...>
> wrote:
>
>> Hi Karol,
>>
>> I suppose that NO coefficients and orbital occupation numbers are the
>> same, i.e. they should be the diagonals of the diagonalized density
>> matrix.For single-determinant methods they are 2 (or 1) and for
>> multi-determinant methods they have some value between 0 and 2 (or 1).
>>
>> At least I cannot think of any other meaning of "NO coefficients", but I
>> never heard that term so far.
>>
>> Thanks, I hope that this feature is available soon as it would be pretty
>> nice to use cclib!
>>
>> Cheers
>> Axel
>>
>> On Thu, Oct 23, 2014 at 2:18 PM, Karol Langner <kar...@gm...>
>> wrote:
>>
>>> Hi Axel,
>>>
>>> The attribute nocoeffs parses NO coefficients, and only for Gaussian at
>>> the moment, I believe. It could be easily extended to other programs,
>>> assuming our test logfiles contain the data.
>>>
>>> If I understand correctly, occupation numbers can be calculated from the
>>> NO coefficients. Is that correct?
>>>
>>> Cheers,
>>> Karol
>>>
>>>
>>> On Thu, Oct 23, 2014 at 3:40 AM, Axel Schild <axe...@go...
>>> > wrote:
>>>
>>>> Hi,
>>>>
>>>> I'm one of the developers of orbkit (
>>>> http://sourceforge.net/projects/orbkit). So far, we are using our own
>>>> Molden, GAMESS US, Gaussian log-file/fchk-file, and WFN-file parser, but we
>>>> thought about (also) using cclib to be able to read all the file formats
>>>> that you support.
>>>>
>>>> However, we need orbital occupation numbers (like those of MCSCF
>>>> orbitals or of natural orbitals).
>>>>
>>>> Is this the data that is stored in the variable <nocoeffs> in the
>>>> development version? If so, will it be available for any other than the
>>>> GAMESS and Gaussian parsers anytime soon? If not, is this feature planned
>>>> to be included?
>>>>
>>>> Cheers
>>>> Axel
>>>>
>>>>
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>>>>
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>>>>
>>>
>>
>