Dear all,

Many thanks for the answers a= nd for the helpful references.

Dave Close- Thank y= ou 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 sy= stems 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 t= op of these geometries. I am looking for a higher level of theory (again pu= rely in terms of the electronic structure, i.e single-point energy calculat= ions on the same geometry) with which to compare the DFT results. I am inte= rested in both gas phase and solution (implicit model such as PCM). Would y= ou then recommend CCSD?

Best wishes,

Scott =A0=A0

On 17 = October 2013 18:29, Close, David M. CLOSED+/-mail.etsu.edu <owner-chemistry()ccl.net> wrote:<= br>

Sent to CCL by: "Close, David M." [CLOSED++mail.etsu.edu]
Scott:
=A0 I have several answers to your question. =A0But first it is important t= o ask how big your systems are. =A0It may be very time consuming to use CCS= D on a large system. =A0Next it is important to know if you have benchmark = experimental results to compare your calculations with.
=A0 Having said that, I would recommend the paper by Verdolino et al (J. Ph= ys. Chem. B 2008, 112, 16860. =A0They did calculations on the nucleobases a= nd got results in good agreement with experimental values using B3lyp/6-31+= G(d,P) opts followed by =A0single point aug-cc-pVTZ calculations. =A0You do= n't say if you are doing gas phase or solution phase calculations. =A0I= f you are doing PCM calculations this paper is interesting because of metho= ds described to alter the cavity size for the anions and cations.
=A0 But there is another problem even if you have good experimental data. = =A0There are discussions in the literature =A0of whether vertical IP's = in the literature are actually adiabatic IP's. =A0If this is a concern = you should look at Hildenbrand, Int. J. Mass Spect. 2000, 197, 237.

=A0 Regards, Dave Close.

-----Original Message-----
> From: owner-chemistry+closed=3D=3Detsu.edu#ccl.net [mailto:owner-chemistry+closed=3D=3Detsu.edu#ccl.net] On Behalf Of Scott Mckechn= ie 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 =A0Mckechnie" [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 f= unctionals and basis sets. I've noticed CCSD(T) is commonly used and I&= #39;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/c= hemistry/sub_unsub.shtmlhttp://www.ccl.net/spammers.txt

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--047d7b6dc31ee551c504e8f53d83-- From owner-chemistry@ccl.net Thu Oct 17 21:47:00 2013 From: "Prof Ponnadurai Ramasami ramchemi|intnet.mu" To: CCL Subject: CCL: Call for Full Paper-8th Workshop on Computational Chemistry and Its Applications-Part of ICCS 2014 Message-Id: <-49255-131017214019-4263-0K2KH24n2W2wUfPBkvEb9A\a/server.ccl.net> X-Original-From: "Prof Ponnadurai Ramasami" Content-Language: en-gb Content-Type: multipart/alternative; boundary="----=_NextPart_000_003E_01CECBC4.817A5670" Date: Fri, 18 Oct 2013 05:40:08 +0400 MIME-Version: 1.0 Sent to CCL by: "Prof Ponnadurai Ramasami" [ramchemi a intnet.mu] This is a multipart message in MIME format. ------=_NextPart_000_003E_01CECBC4.817A5670 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Dear Sir/Madam The 8th Workshop on Computational Chemistry and Its Applications (8th = CCA) will be organized as part of the International Conference on = Computational Science (ICCS 2014). ICCS 2014 will be held from 10 to 12 June 2014 in Cairns, Australia. http://iccs2014.ivec.org/ You are invited to submit full paper/s to be considered for the 8th CCA workshop.=20 Prof Michelle Coote from the = Australian National University, Australia, will deliver the keynote address = entitled "Computer-aided design of stereocontrol agents for radical = polymerization". All details are available on the workshop webpage, http://sites.uom.ac.mu/cca/ All papers will be peer-reviewed and accepted papers (oral or poster) = will be published in Procedia Computer Science (http://www.elsevier.com/journals/procedia-computer-science/1877-0509/gui= de- for-authors) Looking forward to receiving your full paper/s. Let me know if you have any queries. Kind regards. Prof Ponnadurai Ramasami=20 8th CCA Workshop Organizer Professor Ponnadurai Ramasami | FRSC, FICCE, CSci, CChem | ? = Computational Chemistry Group, Department of Chemistry, Faculty of Science, University = of Mauritius, R=E9duit, Mauritius | Tel: ) +230 403-7507 | Fax: 6 +230 = 465-6928 | | + ramchemi],[intnet.mu | =FF www.uom.ac.mu | =FF www.uom.ac.mu/sites/CCUOM/index.html | < Chemistry I Computational I Chemistry > =3D Useful results < Chemistry = I Chemistry > =FC Please think about the environment. Print this email only if = required. P Think green. Think before you print. =20 =20 =20 ------=_NextPart_000_003E_01CECBC4.817A5670 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Dear = Sir/Madam

The 8th Workshop on = Computational Chemistry and Its Applications (8^th CCA) will be organized as part of = the International Conference on Computational Science (ICCS = 2014).

ICCS 2014 will be held from 10 = to 12 June 2014 in Cairns, Australia.

http://iccs2014.ivec.org/

You are invited to submit full = paper/s to be considered for the 8^th CCA workshop. =

Prof Michelle Coote from the Australian National University, Australia, = will deliver the keynote address entitled "Computer-aided design of stereocontrol agents for radical = polymerization".

All details are available on the = workshop webpage, http://sites.uom.ac.mu/cca/

All papers will be peer-reviewed = and accepted papers (oral or poster) will be published in Procedia Computer = Science (http://www.elsevier.com/journals/procedia-computer= -science/1877-0509/guide-for-authors)

Looking forward to receiving = your full paper/s.

Let me know if you have any = queries.

Kind = regards.

Prof Ponnadurai Ramasami =

8^th CCA Workshop = Organizer

<= ; Chemistry I Computational I Chemistry > =3D Useful results < = Chemistry I Chemistry >

=FC Please = think about the environment. Print this email only if required. &= nbsp;

P = Think green. Think before you print.

------=_NextPart_000_003E_01CECBC4.817A5670--