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Miscellaneous / NEB job
« Last post by saikat403 on Today at 08:26:05 am »
 I was looking modules in turbomole 7.3. For NEB method I have found two module, woelfling-job and nebmjob. I can't find anything about the second one i.e. nebmjob. I have tried woelfling-job.
But how to use this nebmjob and what is the difference between them.

with regards,
Ricc2 / Queerness/Issue observed with RI-basis set
« Last post by evgeniy on November 20, 2019, 01:26:48 pm »

I encountered the following, at first glance counter-intuitive result for an rimp2 calculation for a deprotonated (anionic) closed-shell molecule.
Since it is anion diffuse functions could be important. So, I set up a mp2 calculation using the aug-cc-pVDZ basis set.
For some reason I changed only the main basis to aug-cc-pVDZ but the auxiliary basis (cbas), which was set to cc-pVDZ. This is case 1.
When I saw the inconsistency, I repeated the calculation with the right, i.e. aug-cc-pVDZ, auxiliary basis set. This is case 2.
When I compared the mp2 energies in case 1 and 2 I found out that the mp2 energy in case 1 (inconsistent cbas basis set)  is slightly
(~0.2 kcal/mol) lower than the energy in case 2 (the main and cbas basis sets are consistent). This was unexpected as I thought that
the larger the cbas basis set, the more closer the result to that obtained without the use of RI. In fact it turned out that the mp2 energy
obtained with the smaller cbas basis set, i.e. case 1, is slightly lower than the mp2 energy obtained without the use of RI.

I wounder whether the above described queerness is known and what the reason of it is (can be)?

Best regards,
Ricc2 / Re: Negative excitation energies in ADC(2)
« Last post by christof.haettig on November 18, 2019, 11:58:07 am »
Arnim is right. The CCS calculations shows that the system is close to a singlet instability or even has a singlet instability.
This is not unusual in excited state geometry optimizations: If you break along the relaxation pathway a bond, the ground state energy increases a lot and the gap between the excited and the ground states gets small.

The CI between an excited and the ground state can not be described with response methods. For that you have to go the multireference methods.
If you are not interested in the details of the CI, but only on its approximate position you can ignore the problem.
To model the deactivation after reaching the CI you can continue the geometry optimization (or IRC or DRC run) on the ground state potential energy surface (for ADC(2) that is MP2).
Ricc2 / Re: RICC2 excited state multiplicity
« Last post by christof.haettig on November 18, 2019, 11:44:21 am »
If you run for a triplet ground state it means you run an open-shell calculation. This uses in the ricc2 part spin-orbitals (because it needs diagonal occupied/occupied and virtual/virtual blocks of the Fock matrix), i.e. different MOs for alpha and beta spin.
With that  you don't get pure singlet and pure triplet states but states with some spin contamination.

So, the multiplicity input has no meaning for these calculations and is ignored.

To determine the approximate spin multiplicity of the states you can compute the expection values for S^2 with the s2expect keyword in the $excitations and $response data groups
Ricc2 / Re: how to calculate spin-orbit coupling with CC2/ADC(2)?
« Last post by christof.haettig on November 18, 2019, 11:34:16 am »
This is not yet implemented. It is only available between singlet GS and triplet ES.
Ricc2 / Re: Geometry optimization of the lowest triplet state
« Last post by christof.haettig on November 18, 2019, 11:31:51 am »
You start from a closed-shell SCF?
Ricc2 / Re: Crash on the calculation of excited state with ADC(2)/COSMO
« Last post by christof.haettig on November 18, 2019, 11:26:00 am »
Looks like a problem with the stack size. Check that your job can create a sufficiently large stack in the OMP-parallel parts. What is sufficient depends on the system size. Yours is quite large. Might need something like 1 GB.
Ricc2 / Re: ADC(2)/COSMO oscillating macro-iteration
« Last post by christof.haettig on November 18, 2019, 11:17:51 am »
If the gap between the ground and the lowest excited state is so small that they interchange from vacuum to solution this can cause problems for the PTED-COSMO calculations.
Check if the occupation of the orbitals after the COSMO-SCF is correct.
Great cheers, will do that!
Ridft, Rdgrad, Dscf, Grad / Re: ridft+dsp problem with Curium/HOH
« Last post by corey.taylor on November 15, 2019, 04:53:45 pm »
Cheers Uwe. However...

Code: [Select]
   |            DFT-D4            |
   |          ==========          |
   |  E. Caldeweyher,  S. Grimme  |
   |   University of Bonn, MCTC   |
   |     02/2018, Version 1.0     |
  This code comes without any warranty
  This code comes without any warranty

 Found param_gfn2.xtb file !
    G F N  parametrization, version 3
   Geometries Frequencies Non-covalent interactions
 method parameters:
k(s)        :               1.8500
k(p)        :               2.2300
k(d)        :               2.2300
k(f)        :               2.0000
kEN (H0ij)  :              -2.0000
D3 a1       :               0.5200
D3 a2       :               5.0000
D3 s8       :               2.7000
D3atm       :               5.0000
alphaj      :               2.0000
AESdamp     :               4.0000
AESrad      :               3.0000
expscalexp  :               5.0000
 xTB basis
#ERROR! f-functions not implemented

I didn't find an option in define so just changed $disp3 to $disp4. Did I miss something in the setup?
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