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Alexandr
planfactor@mail.ru

>I study methods spectrophotometry diluted (10-5 _10-6 M) water solutions of various acidity of organic substances of a class trioxyfluorone (TOF). I should establish an order dissociation protons of three hydroxyl groups TOF. For calculation of frequencies in an electronic spectrum used TDDFT. I wish to calculate sets of frequencies for all variants dissociation TOF. At once there was a problem. I have received a spectrum of absorption of solution TOF in the known form for it in water. In attached files (Doc1 - Doc 3) comparison of this spectrum of a solution of particle TOF (a red line) to the calculated frequencies is resulted. In vacuum (Doc 1 for comparison) with hybrid functional B3LYP artefacts of frequencies are found out at 639 and 1427 nanometers (it is natural). To get rid of artefacts I used method PCM with the same hybrid functional B3LYP (Doc 2) and with a functional with the increased weight HF of exchange - BHHLYP (Doc 3). As a result I had a suspicion that among existing set of functionals always will be such which by the criteria accepted by us will allow to describe well to (explain) any experimental data?. But after all it is elementary adjustment to the given connection. And it is necessary to me, that the method could predict at least frequency of the first long-wave transition of other variants of ions TOF. For example, for considered particle TOF there are three variants dissiciation, for 2-charg an ion - two or three variants and so on are possible. The geometry of these of structure is already optimised by me.
>   Very much I ask you of the help. As to me to change mine a Input file (Doc 4) to solve a problem. Or: what method should be used for this purpose? So, I have found A.Granovskogo's presentation of method XMCQDPT2 from 10.12.2008. However in respect of practical use of this method - in the Internet there is a full fog.
>
> Best regards,
>  Alexandr.
>

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