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lello
raffaele.borrelli@unito.it

I am a bit confused. What happens if I use ISTSYM=2
in an MCSCF calculation and, in the same run I
do an MCQDPT2? Which states are selcted for MP2?

Lello

On Thu Oct 3 '13 3:14pm, Alex Granovsky wrote
---------------------------------------------
>Dear Lello,
>Dear Thom,

>Thom is right that the described convention is used by all CI codes
>which work in AO basis. At present, this are exactly CIS/TDHF/TDDFT.

>The convention for GUGA/ALDET CI is different. In addition,
>XMCQDPT/MCQDPT code applies yet another convention.

>Kind regards,
>Alex Granovsky
>
>
>
>On Thu Oct 3 '13 12:25pm, Thomas Pijper wrote
>---------------------------------------------
>>Dear Lello,

>>AFAIK, the information in the manual is correct. My guess is that different parts of the Firefly code number the irreps differently. The numbering on page 121 pertains to the TDHF/TDDFT/CIS code, while the second numbering you refer to (ISTSYM=4 for Bu in C2h) pertains to the (X)MCQDPT2 code. Perhaps Alex can provide more information (or correct me if I'm wrong).

>>Page numbers will be added in the next update.
>>
>>
>>Kind regards,
>>Thom
>>
>>
>>
>>
>>On Thu Oct 3 '13 11:07am, lello wrote
>>-------------------------------------
>>>Dear All,

>>>concerning the manual I have found some contradictory information
>>>about the use of symmetry with ISTSYM.

>>>The manual (on page 121) states that the number ISTSYM associated with the symmetry label can be found looking at the string
>>>"DIMENSIONS OF THE SYMMETRY SUBSPACES"

>>>The example gives ISTSYM=3 for the Bu label in C2h group.
>>>Later in the manual one finds that ISTSYM=4 for Bu in C2h.
>>>The main problem is that I am performing a CASSCF in C2h symmetry
>>>and I must use ISTSYM=2 to get Bu states.

>>>Am I doing something wrong or is there some error in the manual?

>>>Also, is it possible to add page number to the manual?

>>>Thanks,
>>>Lello

>>>On Wed Oct 2 '13 3:46pm, Thomas Pijper wrote
>>>--------------------------------------------
>>>>Dear all,

>>>>The Firefly manual has been updated today. The new files can be found in the "Manuals" section.
>>>>
>>>>
>>>>Kind regards,
>>>>Thom