Dear All,
I want to calculate the phosphorescence and SOC of transitionmetal Pt complexes. listed below are my input and output files, I am not sure it is right or wrong? Could anyone give me some advice?
**DALTON INPUT
.RUN RESPONSE
**INTEGRALS
.SPINORBIT
**WAVE FUNCTION
.DFT
B3LYP
**RESPONSE
*QUADRATIC
.PHOSPHORESCENCE
.ROOTS
1
**END OF DALTON INPUT
the part of output file
Phosphorescence  length gauge:
Oscillator strength (/2PI) (H_SO) 3.848929E09
Dipole strength [a.u.] (H_SO) 2.115217E06
Dipole strength E40 [esu**2 cm**2] 1.366530E01
Total transition rate (H_SO) 7.617659E02 s1
Total phosphorescence lifetime (H_SO) 1.312739E+01 s
the lifetime is much longer than experiment result, and what is the "Total transition rate"? how to analyze the spinorbit coupling and the spinorbit constant?
How to calculate phosphorescence and spinorbit coupling

 Posts: 5
 Joined: 06 Apr 2015, 14:56
 First name(s): Bao
 Last name(s): Yang
 Affiliation: CCZU
 Country: China
Re: How to calculate phosphorescence and spinorbit coupling
The input is correct. DFT is not known for its predictive power when it comes to transitionmetal compounds, in particular for nonstandard properties like this.
Please look up "transition rate" in any textbook on quantum mechanics.
If you by SOC mean the singlettriplet transition matrix element, it is a separate type of calculation in Dalton, see e.g. the rsp_lrso test case in the distribution.
Regards,
Olav
You
Please look up "transition rate" in any textbook on quantum mechanics.
If you by SOC mean the singlettriplet transition matrix element, it is a separate type of calculation in Dalton, see e.g. the rsp_lrso test case in the distribution.
Regards,
Olav
You

 Posts: 5
 Joined: 06 Apr 2015, 14:56
 First name(s): Bao
 Last name(s): Yang
 Affiliation: CCZU
 Country: China
Re: How to calculate phosphorescence and spinorbit coupling
Hi Olav, Thanks a lot for your reply.
Actually, I want to calculate the singlettriplet transition matrix element. So I checked the rsp_lrso test and searched the keywords in Dalton2015 manual, My molecule has 298 electrons and 858 orbitals, I think it is a big molecule for soc calculation, so how to set the ".INACTIVE SPACE" and ".CAS SPACE" if we take account of calculation time and accuracy? Thanks in advance
**DALTON INPUT
.RUN RESPONSE
.NEWTRA
**INTEGRALS
.SPINORBIT
**WAVE FUNCTIONS
.MCSCF
*CONFIGURATION INPUT
.SYMMETRY
1
.SPIN MULTIPLICITY
1
.INACTIVE SPACE
.ELECTRONS
2
.CAS SPACE
*CI VECTOR
.PLUS COMBINATIONS
*OPTIMIZATION
.DETERMINANTS
**RESPONSE
.TRPFLG
*LINEAR
.SINGLE RESIDUE
.SPINORBIT
**END OF DALTON INPUT
Actually, I want to calculate the singlettriplet transition matrix element. So I checked the rsp_lrso test and searched the keywords in Dalton2015 manual, My molecule has 298 electrons and 858 orbitals, I think it is a big molecule for soc calculation, so how to set the ".INACTIVE SPACE" and ".CAS SPACE" if we take account of calculation time and accuracy? Thanks in advance
**DALTON INPUT
.RUN RESPONSE
.NEWTRA
**INTEGRALS
.SPINORBIT
**WAVE FUNCTIONS
.MCSCF
*CONFIGURATION INPUT
.SYMMETRY
1
.SPIN MULTIPLICITY
1
.INACTIVE SPACE
.ELECTRONS
2
.CAS SPACE
*CI VECTOR
.PLUS COMBINATIONS
*OPTIMIZATION
.DETERMINANTS
**RESPONSE
.TRPFLG
*LINEAR
.SINGLE RESIDUE
.SPINORBIT
**END OF DALTON INPUT

 Posts: 545
 Joined: 15 Oct 2013, 05:37
 First name(s): Peter
 Middle name(s): Robert
 Last name(s): Taylor
 Affiliation: Tianjin University
 Country: China
Re: How to calculate phosphorescence and spinorbit coupling
I am going to make some suggestions here that I hope you will take as constructive thinking, rather than criticism. But it seems to me that launching immediately into trying to calculate phosphorescence lifetimes for a Pt complex (you do not give any information as to the structure of the molecule) that your current calculation involves almost 900 basis functions and 300 electrons, and deciding that because DFT/B3LYP gives unsatisfactory results you will switch to CASSCF is somewhat akin to someone who decides to learn to drive, and having had a negative experience trying to learn by driving a 40ton 18wheeler truck, thinks that switching to a Formula 1 race car is a better alternative. As just one issue to consider, an MCSCF calculation will not run integraldirect, and you will therefore have to cope with disk storage of integrals. If most of the integrals are nonzero (again, without knowing your molecule it is impossible to say) you will need over 1TB of disk for the integrals and labels, plus additional disk needed to sort and transform integrals. Furthermore, this method is not parallelized and the computer time will likely be nontrivial.
My thinking is that you would be much better advised to find a model Ptcomplex that exhibits at least some of the features of your target molecule, but which is considerably smaller. Replacing larger ligands with "stubs", such as replacing, say, triphenylphosphines with PH$_3$ groups, or an Sbound cysteine with an SH group, should at least provide a start. I stress this because CASSCF and MCSCF more generally is very far from a blackbox approach! It is often necessary to look at expanding or shrinking the active space to get a balanced (I say "balanced" here, not necessarily "accurate"!) description of different electronic states. In addition, model complexes can often be constructed that have higher symmetries than C$_1$, which not only reduces the computation time but makes the identification of particular excited states much easier.
Once you have investigated such a model at a higher level, like CASSCF, you can then compare it to DFT approaches. If you find one that agrees reasonably well with your model system CASSCF calculation, it is at least plausible, although by no means guaranteed, that this agreement would hold for your target molecule. If you find no DFT approach agrees with the higherlevel calculation for your model system, the odds are, unfortunately, that no DFT approach will be acceptable for your target system.
This general approach  find a model system that is at least some sort of approximation to your desired system but which is amenable to a range of highlevel treatments, and use this model to calibrate more approximate methods, is something that many of us, including myself, have been advocating for many years. Indeed, if you can get hold of a copy of the lecture notes from the biennial European Summerschool in Quantum Chemistry, you will find a detailed article of mine on how to use this philosophy. The notes are now old and omit many methods one might use today, but the philosophy, I submit, is still sound...
Best regards
Pete
My thinking is that you would be much better advised to find a model Ptcomplex that exhibits at least some of the features of your target molecule, but which is considerably smaller. Replacing larger ligands with "stubs", such as replacing, say, triphenylphosphines with PH$_3$ groups, or an Sbound cysteine with an SH group, should at least provide a start. I stress this because CASSCF and MCSCF more generally is very far from a blackbox approach! It is often necessary to look at expanding or shrinking the active space to get a balanced (I say "balanced" here, not necessarily "accurate"!) description of different electronic states. In addition, model complexes can often be constructed that have higher symmetries than C$_1$, which not only reduces the computation time but makes the identification of particular excited states much easier.
Once you have investigated such a model at a higher level, like CASSCF, you can then compare it to DFT approaches. If you find one that agrees reasonably well with your model system CASSCF calculation, it is at least plausible, although by no means guaranteed, that this agreement would hold for your target molecule. If you find no DFT approach agrees with the higherlevel calculation for your model system, the odds are, unfortunately, that no DFT approach will be acceptable for your target system.
This general approach  find a model system that is at least some sort of approximation to your desired system but which is amenable to a range of highlevel treatments, and use this model to calibrate more approximate methods, is something that many of us, including myself, have been advocating for many years. Indeed, if you can get hold of a copy of the lecture notes from the biennial European Summerschool in Quantum Chemistry, you will find a detailed article of mine on how to use this philosophy. The notes are now old and omit many methods one might use today, but the philosophy, I submit, is still sound...
Best regards
Pete

 Posts: 17
 Joined: 19 Feb 2015, 13:31
 First name(s): Bernd
 Last name(s): Schimmelpfennig
 Affiliation: KIT
 Country: Germany
Re: How to calculate phosphorescence and spinorbit coupling
Peter has summed up already a lot of important points but I dare to add one more:
For a Pt complex you need to include relativity in some form and in case you go for the cheap way by using a pseudopotential the spinorbit integrals provided by DALTON will not be generated with the correct Hamiltonian. Even with an allelectron basis set and scalar relativity you should be careful about the correct SOoperator. This is independent of using MCSCF or DFT.
Best,
Bernd
For a Pt complex you need to include relativity in some form and in case you go for the cheap way by using a pseudopotential the spinorbit integrals provided by DALTON will not be generated with the correct Hamiltonian. Even with an allelectron basis set and scalar relativity you should be careful about the correct SOoperator. This is independent of using MCSCF or DFT.
Best,
Bernd

 Posts: 545
 Joined: 15 Oct 2013, 05:37
 First name(s): Peter
 Middle name(s): Robert
 Last name(s): Taylor
 Affiliation: Tianjin University
 Country: China
Re: How to calculate phosphorescence and spinorbit coupling
Thanks very much to Bernd for the additional information: I was myself a bit worried about this aspect but felt it was too far outside my expertise to be commenting on. As you see, there is very much to consider in doing these calculations!
Best regards
Pete
Best regards
Pete

 Posts: 5
 Joined: 06 Apr 2015, 14:56
 First name(s): Bao
 Last name(s): Yang
 Affiliation: CCZU
 Country: China
Re: How to calculate phosphorescence and spinorbit coupling
Thank you all, Pete and Bernd. What about ADF in calculating spinorbit of Pt complexes ?

 Posts: 17
 Joined: 19 Feb 2015, 13:31
 First name(s): Bernd
 Last name(s): Schimmelpfennig
 Affiliation: KIT
 Country: Germany
Re: How to calculate phosphorescence and spinorbit coupling
ADF should be able to do it with TDDFT including SOcoupling either from the beginning or as a perturbation.
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