magnetic transition dipole moments between excited states

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marand71
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Joined: 03 Mar 2015, 12:55
First name(s): Marcin
Last name(s): Andrzejak
Affiliation: Theoretical Chemistry Department, Jagiellonian University
Country: Poland

magnetic transition dipole moments between excited states

Post by marand71 » 03 Mar 2015, 13:04

Dear Dalton Experts

I am a newbie in Dalton, so please forgive me if I am asking fairly obvious questions.

I am trying to compute transition magnetic dipole moments between a pair of excited states of an organic molecule (e.g. phthalimide) in order to further simulate the MCD spectrum with vibronic resolution. To do that I need the sum-over-states approach to obtaining the MCD B-terms so the transition magnetic dipole moments between the excited states are essential (alternatively, I could do with the transition angular moments).

Please, advise me on choosing the correct procedure (would *CCQR2R be OK?) and give some tips how to use it.

My best regards!
Marcin Andrzejak

ras
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Joined: 18 Mar 2015, 14:57
First name(s): Rashid
Last name(s): Valiev
Affiliation: TSU
Country: Russian Federation

Re: magnetic transition dipole moments between excited state

Post by ras » 19 Mar 2015, 16:10

I'm connecting to this question.
Dear all!
I need to calculate the matrix elements of angular moment between the excited singlet states and the ground state (triplet!) and their excitation energies using MCSCF level of theory. I have a problem. I can’t find the required results.
My input file:
**DALTON INPUT
.RUN WAVE FUNCTIONS
.RUN RESPONSE
**INTEGRALS
**WAVE FUNCTIONS
.HF
.MCSCF
*SCF INPUT
.DOUBLY OCCUPIED
7
.SINGLY OCCUPIED
2
*CONFIGURATION INPUT
.INACTIVE
4
.ELECTRONS
8
.CAS SPACE
10
.SYMMET
1
.SPIN MULT
3
*OPTIMIZATION
.DETERMINANTS
.THRESH
4.0D-05
**RESPONSE
*QUADRA
.DOUBLE RESIDUE
.ROOTS
3
.DIPMAG
**END OF DALTON INPUT


I obtained the results. I can see that only matrix elements between singlets excited states.. What is my mistake?
The part of output-file:
@ Transition moment <B | A - <A> | C> in a.u. for
@ A operator label, symmetry, spin: XANGMOM 1 0
@ B excited state no., symmetry, spin: 1 1 0
@ C excited state no., symmetry, spin: 1 1 0

@ B and C excitation energies, moment: 0.00186665 0.00186665 -0.00000000


@ Transition moment <B | A - <A> | C> in a.u. for
@ A operator label, symmetry, spin: YANGMOM 1 0
@ B excited state no., symmetry, spin: 1 1 0
@ C excited state no., symmetry, spin: 1 1 0

@ B and C excitation energies, moment: 0.00186665 0.00186665 0.00000000


@ Transition moment <B | A - <A> | C> in a.u. for
@ A operator label, symmetry, spin: ZANGMOM 1 0
@ B excited state no., symmetry, spin: 1 1 0
@ C excited state no., symmetry, spin: 1 1 0

@ B and C excitation energies, moment: 0.00186665 0.00186665 0.00000000


@ Transition moment <B | A - <A> | C> in a.u. for
@ A operator label, symmetry, spin: XANGMOM 1 0
@ B excited state no., symmetry, spin: 1 1 0
@ C excited state no., symmetry, spin: 2 1 0

@ B and C excitation energies, moment: 0.00186665 0.00377279 -0.00000230
and etc..

Best regards, Ras.

olav
Posts: 145
Joined: 28 Aug 2013, 06:20
First name(s): Olav
Last name(s): Vahtras

Re: magnetic transition dipole moments between excited state

Post by olav » 19 Mar 2015, 17:31

The output may be confusing, but what you have calculated is a set of transition matrix elements between excited triplet states, because the ground (reference) state is a triplet. The spin value in the output refers to the spin rank of the excitation, not the final state. If you want spin-altering excitations you have to start with a singlet reference state and add the keyword .TRPFLG after **RESPONSE. But note that XANGMOM etc is the orbital angular momentum, which is spin-conserving, so the result of that calculation would be zero as well.

Regards.
Olav

ras
Posts: 2
Joined: 18 Mar 2015, 14:57
First name(s): Rashid
Last name(s): Valiev
Affiliation: TSU
Country: Russian Federation

Re: magnetic transition dipole moments between excited state

Post by ras » 23 Mar 2015, 13:40

olav wrote:The output may be confusing, but what you have calculated is a set of transition matrix elements between excited triplet states, because the ground (reference) state is a triplet. The spin value in the output refers to the spin rank of the excitation, not the final state. If you want spin-altering excitations you have to start with a singlet reference state and add the keyword .TRPFLG after **RESPONSE. But note that XANGMOM etc is the orbital angular momentum, which is spin-conserving, so the result of that calculation would be zero as well.

Regards.
Olav
Dear Dr. Olav!
Thank you! Really, I need to calculate the magnetic dipole transition for the system with the triplet ground state (from triplet to singlets) or the matrix elements <|2S+L|>. Can I use it such as

.PHOSPHORESCENCE
but with the angular momentum (.DIPMAG) instead the electric dipole moment?
Best regards, Rashid.

olav
Posts: 145
Joined: 28 Aug 2013, 06:20
First name(s): Olav
Last name(s): Vahtras

Re: magnetic transition dipole moments between excited state

Post by olav » 25 Mar 2015, 09:49

I believe this article describes in part what you are looking for http://www.sciencedirect.com/science/ar ... 0496001267

To do these calculations you always have start from the singlet state, and you can not use the PHOSPHORESCENCE option. For a given Sn->T1 you have to converge the singlet state and set up a response calculation as a single residue quadratic response calculation of the form (all operator components, you have to work out the details)

**RESPONSE
.TRPFLG
*QUADRATIC
.SINGLE RESIDUE
.APROP
XANGMOM
.BPROP
X1SPNORB
.ROOTS
1
.ISPABC
0 1 1

Rashid
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Joined: 02 Feb 2016, 14:55
First name(s): Rashid
Last name(s): Valiev
Affiliation: Tomsk State University
Country: Russian Federation

Re: magnetic transition dipole moments between excited state

Post by Rashid » 17 Mar 2016, 16:59

Thank you very much!
One question. My system has the doublet ground state and I want to calculate the magnetic dipole transitions between doublet and quartet states. Is it possible in Dalton using the quadratic responce theory (MCSCF)?? I only could find the .TRPFLG, no one keywords with doublet and quartet tates.
Thank you!

olav wrote:I believe this article describes in part what you are looking for http://www.sciencedirect.com/science/ar ... 0496001267

To do these calculations you always have start from the singlet state, and you can not use the PHOSPHORESCENCE option. For a given Sn->T1 you have to converge the singlet state and set up a response calculation as a single residue quadratic response calculation of the form (all operator components, you have to work out the details)

**RESPONSE
.TRPFLG
*QUADRATIC
.SINGLE RESIDUE
.APROP
XANGMOM
.BPROP
X1SPNORB
.ROOTS
1
.ISPABC
0 1 1

olav
Posts: 145
Joined: 28 Aug 2013, 06:20
First name(s): Olav
Last name(s): Vahtras

Re: magnetic transition dipole moments between excited state

Post by olav » 18 Mar 2016, 10:16

No, that is not possible
/Olav

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