Search found 280 matches

by xiongyan21
21 Sep 2020, 09:10
Forum: Running Dalton
Topic: Can Dalton calculate oscillator strength
Replies: 50
Views: 7367

Re: Can Dalton calculate oscillator strength

Using the geometry found by spin-flip ORMAS, the vertical T1(MCQDPT)- S0(MCQDPT, by spin-flip MRMP2) can be 0.08 eV deviating from 3.99 eV. Using the geometry found by spin-flip TDDFT PBE0, also a planar one, the vertical T1(MCQDPT)- S0(MCQDPT, by spin-flip MRMP2) can be about 0.29 eV deviating from...
by xiongyan21
19 Sep 2020, 11:24
Forum: Running Dalton
Topic: Can Dalton calculate oscillator strength
Replies: 50
Views: 7367

Re: Can Dalton calculate oscillator strength

Spin-flip OMARS geometry search of the triplet structure of furan, where a planar structure is found. The active orbitals are 115 and the active electrons are 36 in 3 partitions with nstate being equal to 3, where the final energy is significant different from the ROHF one. FCI should be applied to ...
by xiongyan21
18 Sep 2020, 10:03
Forum: Running Dalton
Topic: Potential energy curve of O2
Replies: 5
Views: 4906

Re: Potential energy curve of O2

Prof. Gordon, Prof. Luedenberg, et al. in Ames Lab and US universities have already developed new methods of charaterizing correlation energy, e.g., that of O2 published ten years ago, with sophiscated extrapolation, which increases the FCI archive of GAMESS, but a method very difficult for the desi...
by xiongyan21
08 Sep 2020, 09:53
Forum: Running Dalton
Topic: Can Dalton calculate oscillator strength
Replies: 50
Views: 7367

Re: Can Dalton calculate oscillator strength

I am trying Spin-flip ORMAS-CI, and arbitrarily send the first partition of active space 29 electrons, 36 active electrons in total among which there are 19 alpha and 17 beta electrons based on spin-flip TDDFT. One of the original ORMARS programmer is Dr. M. Schmidt in Ames Lab and Prof. Gordon's gr...
by xiongyan21
07 Sep 2020, 03:16
Forum: Running Dalton
Topic: Can Dalton calculate oscillator strength
Replies: 50
Views: 7367

Re: Can Dalton calculate oscillator strength

Dear Prof. Jensen I have understood the article, Influence of triplet instabilities in TDDFT of Prof.Tozer, an RSC metal winner, et al. in Durham University in United Kindom. By the way, Prof. Tozer is one of the authors of the diagnostic of excited states natures. GAMESS UHF or ROHF TDDFT can only ...
by xiongyan21
06 Sep 2020, 03:09
Forum: Running Dalton
Topic: Can Dalton calculate oscillator strength
Replies: 50
Views: 7367

Re: Can Dalton calculate oscillator strength

As for pyridine, spin-flip TDDFT, although using C1 symmetry a plananr geometry is found, gives vertical T1-S0 gap discrepencies of about 0.12, 0.05 and 0.06 eVs using PBE0, B3LYP and B3LYPV1R(matching electron gas formula in some packages), respectively, when compared with the experimental data of ...
by xiongyan21
04 Sep 2020, 12:20
Forum: Running Dalton
Topic: Can Dalton calculate oscillator strength
Replies: 50
Views: 7367

Re: Can Dalton calculate oscillator strength

For the spin-flip found triplet geometry with 6-31+G(d,p) the lengths of NC, CC, CH are 0.056, 0.045, 0.01 Bohrs deviating from the empirically corrected values of 3B3u reported in J. Phys. Chem, and the bond angles are about 2, 1, 1 degrees different, the discrepencies from those of MCSCF STO-3G wi...
by xiongyan21
03 Sep 2020, 03:40
Forum: Running Dalton
Topic: NMR calculation of Si(CH3)4 not converged
Replies: 38
Views: 5896

Re: NMR calculation of Si(CH3)4 not converged

I forgot to give shielding constants previously got by NWCHEM7.0.0 of Si(CH3)4 in CCl4 using B3lyp and 6-311G e.g., Atom: 15 H Diamagnetic ... Paramagnetic ... Total Shielding Tensor ... isotropic = 33.0510 ... Today, NWCHEM7.0.0 B3lyp and 6-311+G(d,p) gives that of isotropic = 32.1737 Those of all ...
by xiongyan21
28 Aug 2020, 15:59
Forum: Running Dalton
Topic: Can Dalton calculate oscillator strength
Replies: 50
Views: 7367

Re: Can Dalton calculate oscillator strength

Dear Prof. Jessen Thanks a lot for your elaboration, which makes me know one triplet structure obtained from one operator may not be stable when using others. For the first excited state of thiabendazole searched in water, both Hessian analysis methods exhibit no imaginary frequency. As for pyrazine...
by xiongyan21
28 Aug 2020, 00:02
Forum: Running Dalton
Topic: Can Dalton calculate oscillator strength
Replies: 50
Views: 7367

Re: Can Dalton calculate oscillator strength

All the Dalton2018 calculations on Ubuntu 18.04 may need to be carefully examined, because although they are finished and the results can be compared with experimental data, it may contain serious errors.

Very Best Regards!
by xiongyan21
27 Aug 2020, 10:06
Forum: Running Dalton
Topic: Can Dalton calculate oscillator strength
Replies: 50
Views: 7367

Re: Can Dalton calculate oscillator strength

With GAMESS the UHF optimization of pyrazine in vacuum with the increased convergence tightness, 6-31+G(d,p) and pbe0 gives an imaginary frequency about 172 cm^-1, and when the basis set is changed into 6-311++G(2d,2p), that becomes about 260 cm^-1. The adiabatic T1-S0 gap after ZPVE(~0.21 eVs) is w...
by xiongyan21
25 Aug 2020, 09:32
Forum: Running Dalton
Topic: Can Dalton calculate oscillator strength
Replies: 50
Views: 7367

Re: Can Dalton calculate oscillator strength

The phosphorescence emission calculated with Dalton2018 wit 6-31++G** for pyrazine in vacuum using geometry found by spin-flip TDDFT with GAMESS is within 0.1 eVs deviating from the experimental value and the phosphorescence liftime less than 0.06-0.08 seconds. Neverthless, in the terminal, there is...
by xiongyan21
23 Aug 2020, 12:55
Forum: Running Dalton
Topic: Can Dalton calculate oscillator strength
Replies: 50
Views: 7367

Re: Can Dalton calculate oscillator strength

According to Prof. Nguyen: "A mean absolute error ~MAE! of 0.08 eV is obtained by B3LYP/6-311G(d,p) for 37 experimental energies of organic chromophores. Interestingly, the MAE increases to 0.14 eV after including zero-point energy corrections." The increase of convergence tightness and the use of 6...
by xiongyan21
22 Aug 2020, 05:32
Forum: Running Dalton
Topic: Can Dalton calculate oscillator strength
Replies: 50
Views: 7367

Re: Can Dalton calculate oscillator strength

Spin-flip TDDFT with GAMESS using 6-31G(d,p) of gaseous pyrazine give T1-S0 gap around 0.12 eVs deiviating from Prof. Nguyen's TDDFT theoretical work with 6-31+G(d,p) published in JCP before, and about 0.18 eVs deviating from the experimental data indexed there. This triplet geometry is very easy t...
by xiongyan21
18 Aug 2020, 07:42
Forum: Running Dalton
Topic: Can Dalton calculate oscillator strength
Replies: 50
Views: 7367

Re: Can Dalton calculate oscillator strength

Using the triplet geometry found by Spin-Flip TDDFT in ethanol with GAMESS and with the following input for Dalton 2018 and 6-31G **DALTON INPUT .DIRECT .PARALLEL .RUN RESPONSE **INTEGRALS .SPIN-ORBIT **WAVE FUNCTIONS .DFT B3LYP *SCF INPUT **RESPONS *QUADRATIC .ECPHOS .PHOSPHORESCENCE .PRINT 10 .ROO...
by xiongyan21
16 Aug 2020, 07:03
Forum: Running Dalton
Topic: Can Dalton calculate oscillator strength
Replies: 50
Views: 7367

Re: Can Dalton calculate oscillator strength

Dear Prof. Jensen Thanks a lot for your explanation. I first try TDDFT in TDA with Dalton2018, know TD-CIS should be done also with the specification of .CI, and am going to try TD-CISD. By the way, spin-flip TDDFT geometry search with GAMESS using b3lyp and 6-31G(d,p) of phenyl methyl ketone can gi...
by xiongyan21
13 Aug 2020, 12:11
Forum: Running Dalton
Topic: Can Dalton calculate oscillator strength
Replies: 50
Views: 7367

Re: Can Dalton calculate oscillator strength

TD-CIS in GAMESS using 6-31++G(d,p) predicts the oscillator strength of the first and the fourth excitation energies are very small, and the transition dipole of the z direaction and the oscilator strength of the fourth is only the half of the first, and the excitation energy of the first is far fro...
by xiongyan21
12 Aug 2020, 10:49
Forum: Running Dalton
Topic: Can Dalton calculate oscillator strength
Replies: 50
Views: 7367

Re: Can Dalton calculate oscillator strength

Are there methods in Dalton 2018 to treat double excitations and above in the existence of solvation? I don‘t know whether Prof. Truhlar's new method, the combination of MCSCF and DFT together, which may always overcome the difficulties of KS-DFT in multiconfigurational problems, transition metal ch...
by xiongyan21
07 Aug 2020, 10:37
Forum: Running Dalton
Topic: Can Dalton calculate oscillator strength
Replies: 50
Views: 7367

Re: Can Dalton calculate oscillator strength

It should be noted that if the small basis set is used, the excited energies calculated near 200 nms may not be compared with experimental data in terms of eV., and perhaps even using aug-cc-pvdz and any functional, TDDFT results may also fail in the VUV and other regions in terms of eV. Very Best ...
by xiongyan21
03 Aug 2020, 10:53
Forum: Running Dalton
Topic: Can Dalton calculate oscillator strength
Replies: 50
Views: 7367

Re: Can Dalton calculate oscillator strength

CAS 864237-81-0, a pesticide, is difficult to optimize, because it requires a lot of Monte Carlo search steps, and the final geometry is obtained using 6-311++G(2d,2p) and B3lyp, all with GAMESS. PCM in water, 6-31++G(d,p) and b3lyp excitation energies can be compared with the expeimental data in an...
by xiongyan21
01 Aug 2020, 00:27
Forum: Running Dalton
Topic: Can Dalton calculate oscillator strength
Replies: 50
Views: 7367

Re: Can Dalton calculate oscillator strength

The 6-311++G(2d,2p) B3lyp frequency analysis with GAMESS has no imaginary frequency and no warning, meaning a true minimum obtained on the PES, which was first through Monte Carlo search. That is good because it seems the optimization is not easy. I have used RHF and 6-31++G** to calculate ECD by Da...
by xiongyan21
29 Jul 2020, 06:01
Forum: Running Dalton
Topic: Can Dalton calculate oscillator strength
Replies: 50
Views: 7367

Re: Can Dalton calculate oscillator strength

An article in China suggested that it has two maximum wavelengths at 204 and 265 nm in 70% hexane, and said the area of the first one is very large, using Shimadzu LC-20AD. CAMQTP01 gives the first one. the fouth, 0.06 eVs deviating from the experimental data, using 6-31++G(d,p), but it gives the i...
by xiongyan21
28 Jul 2020, 09:09
Forum: Running Dalton
Topic: Can Dalton calculate oscillator strength
Replies: 50
Views: 7367

Re: Can Dalton calculate oscillator strength

During the aug-cc-pvdz and b3lyp calculation of the above using 6-311++G(d,p) with b3lyp optimized geometry, at the beginnning of the DFT response employing Dalton2018, there is a warning ********* WARNING ORBDIA *********** DIAGONAL ORBITAL HESSIAN HAS 1 NEGATIVE ELEMENTS ... Perhaps .INA setting i...
by xiongyan21
27 Jul 2020, 07:02
Forum: Running Dalton
Topic: Can Dalton calculate oscillator strength
Replies: 50
Views: 7367

Re: Can Dalton calculate oscillator strength

CAS 1185987-44-3 has been optimized with 6-311++G(2d,2p), and the excitation energies in hexane have been calculated with 6-31+G(d,p), all with GAMESS, finding three weak absoptions together can give the first experimetal peaks in an article published in China using Shimadzu LC一20AD where the middle...
by xiongyan21
27 Jul 2020, 03:47
Forum: Running Dalton
Topic: Can Dalton be used to obtain ionization potential
Replies: 2
Views: 407

Re: Can Dalton be used to obtain ionization potential

Dear Prof. Jensen
Thanks a lot for your explanation.
GAMESS has added two functionals modified from camb3lyp for ionization potentials, contributed by Dr. Gerasimov in A.N.Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences.


Very Best Regards!