From owner-chemistry@ccl.net Fri Oct 18 07:29:00 2013 From: "Anna Chrostowska anna.chrostowska[-]univ-pau.fr" To: CCL Subject: CCL: Accurate vertical ionization energies Message-Id: <-49256-131018041041-22197-fRfvDcYivai6ntHibP+3VA-,-server.ccl.net> X-Original-From: Anna Chrostowska Content-Type: multipart/alternative; boundary="------------090506080400000705040803" Date: Fri, 18 Oct 2013 10:10:19 +0200 MIME-Version: 1.0 Sent to CCL by: Anna Chrostowska [anna.chrostowska-.-univ-pau.fr] This is a multi-part message in MIME format. --------------090506080400000705040803 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Hi Scott, you can also have a look for IEs calculations of small molecules at: - Comparative Study of Different Methods of Calculation of Ionization Potentials of Small Molecules. /Journal of Physical Chemistry, A/, *2005*, /109/, 8348-8355. - /Chem.Commun./, *2008*, 4204--4206. - /J.Am.Chem.Soc/. *2012*, /134/, 10279-10285*. * or bigger ones: - /Organometallics/ *2010*, /29/, 5192--5198. - /Eur. J. Inorg. Chem. /*2010*, /34/, 5416--5425. - /Dalton Transactions/ *2011*, 40, 4434-4446. /- //Eur. J. Inorg. Chem. /*2011*, 3091--3101. Best wishes, Anna > Dear all, > > Many thanks for the answers and for the helpful references. > > Dave Close- Thank you for your detailed reply. I am looking at organic > molecules up to around 100 atoms in size. I don't have experimental > values for the specific systems of interest so I was thinking of > comparing the performance of various DFT functionals and basis sets > against higher level computational results. The plan was to use B3LYP > optimized geometries and to compare vertical IP values from other > approaches based on single point energy calculations on top of these > geometries. I am looking for a higher level of theory (again purely in > terms of the electronic structure, i.e single-point energy > calculations on the same geometry) with which to compare the DFT > results. I am interested in both gas phase and solution (implicit > model such as PCM). Would you then recommend CCSD? > > Best wishes, > > Scott > > > On 17 October 2013 18:29, Close, David M. CLOSED+/-mail.etsu.edu > > wrote: > > > Sent to CCL by: "Close, David M." [CLOSED++mail.etsu.edu > ] > Scott: > I have several answers to your question. But first it is > important to ask how big your systems are. It may be very time > consuming to use CCSD on a large system. Next it is important to > know if you have benchmark experimental results to compare your > calculations with. > Having said that, I would recommend the paper by Verdolino et al > (J. Phys. Chem. B 2008, 112, 16860. They did calculations on the > nucleobases and got results in good agreement with experimental > values using B3lyp/6-31+G(d,P) opts followed by single point > aug-cc-pVTZ calculations. You don't say if you are doing gas > phase or solution phase calculations. If you are doing PCM > calculations this paper is interesting because of methods > described to alter the cavity size for the anions and cations. > But there is another problem even if you have good experimental > data. There are discussions in the literature of whether > vertical IP's in the literature are actually adiabatic IP's. If > this is a concern you should look at Hildenbrand, Int. J. Mass > Spect. 2000, 197, 237. > > Regards, Dave Close. > > -----Original Message----- > > From: owner-chemistry+closed==etsu.edu#ccl.net > [mailto:owner-chemistry+closed > ==etsu.edu#ccl.net > ] On Behalf Of Scott Mckechnie > jsm78|cam.ac.uk > Sent: Tuesday, October 15, 2013 6:43 AM > To: Close, David M. > Subject: CCL: Accurate vertical ionization energies > > > Sent to CCL by: "Scott Mckechnie" [jsm78 a cam.ac.uk > ] Dear all, > > I would like to compare vertical ionization energies obtained from > DFT with highly accurate energies computed from a higher level > method. I was hoping to get a sense of the accuracy of DFT > ionization energies from different functionals and basis sets. > I've noticed CCSD(T) is commonly used and I'm wondering what > people would recommend. Also, any references would be much > appreciated. > > Best wishes, > > Scotthttp://www.ccl.net/cgi-bin/ccl/send_ccl_messagehttp://www.ccl.net/chemistry/sub_unsub.shtmlhttp://www.ccl.net/spammers.txt > > > > -= This is automatically added to each message by the mailing > script =- > E-mail to subscribers: CHEMISTRY]*[ccl.net > or use:> > E-mail to administrators: CHEMISTRY-REQUEST]*[ccl.net > or use> Conferences: > http://server.ccl.net/chemistry/announcements/conferences/> > > > -- Anna Chrostowska Professeur des Universités Directeur de l'Ecole Doctorale Sciences Exactes et leurs Applications ED 211 ; Université de Pau et des Pays de l'Adour, Institut des Sciences Analytiques et de Physicochimie pour l'Environnement et les Matériaux IPREM, UMR CNRS 5254 ; Avenue de l'Université, 64000 PAU, France TEL +33 (0)5 59 40 75 80 ; +33 (0)5 59 40 74 12 PORTABLE +33603579675 --------------090506080400000705040803 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit

Hi Scott,
you can also have a look for IEs calculations of small molecules at:

- Comparative Study of Different Methods of Calculation of Ionization Potentials of Small Molecules.

Journal of Physical Chemistry, A, 2005, 109, 8348-8355.
-  Chem.Commun., 2008, 4204–4206.

 - J.Am.Chem.Soc. 2012, 134, 10279−10285.


or bigger ones:
-  Organometallics 2010, 29, 5192–5198.

-   Eur. J. Inorg. Chem. 2010, 34, 5416–5425.

- Dalton Transactions 2011, 40, 4434-4446.

- Eur. J. Inorg. Chem. 2011, 3091–3101.

Best wishes,
Anna


Dear all,

Many thanks for the answers and for the helpful references.

Dave Close- Thank you for your detailed reply. I am looking at organic molecules up to around 100 atoms in size. I don't have experimental values for the specific systems of interest so I was thinking of comparing the performance of various DFT functionals and basis sets against higher level computational results. The plan was to use B3LYP optimized geometries and to compare vertical IP values from other approaches based on single point energy calculations on top of these geometries. I am looking for a higher level of theory (again purely in terms of the electronic structure, i.e single-point energy calculations on the same geometry) with which to compare the DFT results. I am interested in both gas phase and solution (implicit model such as PCM). Would you then recommend CCSD?

Best wishes,

Scott   


On 17 October 2013 18:29, Close, David M. CLOSED+/-mail.etsu.edu <owner-chemistry]*[ccl.net> wrote:

Sent to CCL by: "Close, David M." [CLOSED++mail.etsu.edu]
Scott:
  I have several answers to your question.  But first it is important to ask how big your systems are.  It may be very time consuming to use CCSD on a large system.  Next it is important to know if you have benchmark experimental results to compare your calculations with.
  Having said that, I would recommend the paper by Verdolino et al (J. Phys. Chem. B 2008, 112, 16860.  They did calculations on the nucleobases and got results in good agreement with experimental values using B3lyp/6-31+G(d,P) opts followed by  single point aug-cc-pVTZ calculations.  You don't say if you are doing gas phase or solution phase calculations.  If you are doing PCM calculations this paper is interesting because of methods described to alter the cavity size for the anions and cations.
  But there is another problem even if you have good experimental data.  There are discussions in the literature  of whether vertical IP's in the literature are actually adiabatic IP's.  If this is a concern you should look at Hildenbrand, Int. J. Mass Spect. 2000, 197, 237.

  Regards, Dave Close.

-----Original Message-----
> From: owner-chemistry+closed==etsu.edu#ccl.net [mailto:owner-chemistry+closed==etsu.edu#ccl.net] On Behalf Of Scott Mckechnie jsm78|cam.ac.uk
Sent: Tuesday, October 15, 2013 6:43 AM
To: Close, David M.
Subject: CCL: Accurate vertical ionization energies


Sent to CCL by: "Scott  Mckechnie" [jsm78 a cam.ac.uk] Dear all,

I would like to compare vertical ionization energies obtained from DFT with highly accurate energies computed from a higher level method. I was hoping to get a sense of the accuracy of DFT ionization energies from different functionals and basis sets. I've noticed CCSD(T) is commonly used and I'm wondering what people would recommend. Also, any references would be much appreciated.

Best wishes,

Scotthttp://www.ccl.net/cgi-bin/ccl/send_ccl_messagehttp://www.ccl.net/chemistry/sub_unsub.shtmlhttp://www.ccl.net/spammers.txt


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--
Anna Chrostowska Professeur des Universités Directeur de l’Ecole Doctorale Sciences Exactes et leurs Applications ED 211 ; Université de Pau et des Pays de l'Adour, Institut des Sciences Analytiques et de Physicochimie pour l’Environnement et les Matériaux IPREM, UMR CNRS 5254 ; Avenue de l’Université, 64000 PAU, France TEL +33 (0)5 59 40 75 80 ; +33 (0)5 59 40 74 12 PORTABLE +33603579675
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