From owner-chemistry@ccl.net Fri Mar 14 08:49:00 2014 From: "Emilio Xavier Esposito emilio.esposito,,gmail.com" To: CCL Subject: CCL: COMP abstract submission for the San Francisco ACS closes Tuesday, March 18, 2014 Message-Id: <-49851-140314071729-19824-SPTDDxf7W1E5dPaDvJpjkw||server.ccl.net> X-Original-From: Emilio Xavier Esposito Content-Type: text/plain; charset=ISO-8859-1 Date: Fri, 14 Mar 2014 07:17:02 -0400 MIME-Version: 1.0 Sent to CCL by: Emilio Xavier Esposito [emilio.esposito(!)gmail.com] Hi The COMP Programming Board would like to remind you that abstract submissions for the COMP technical program at the San Francisco ACS meeting **closes at 11pm Central Time on Tuesday, March 18, 2014**. Authors can submit their abstract via . Information about COMP events at the San Francisco ACS Meeting (August 10-14, 2014) can be found at the following links: **COMP Symposia at the San Francisco ACS meeting** _Member Contributed Symposia_ _Invited Symposia_ Members are encouraged to submit abstracts to the "Macrocycles in small-molecule drug discovery" symposium. **COMP Awards at the San Francisco ACS meeting** _NVIDIA GPU Award_ _COMP Image Contest_ **Submitting an abstract for the San Francisco ACS meeting and Presenter Information** **Organizing a symposium within COMP at a 2015 (or 2016) ACS National Meeting** Thank you for your time The COMP Programming Board Emilio Xavier Esposito Michael Feig Maciej Haranczyk Eric V Patterson Daniel Sindhikara Yufeng Jane Tseng Scott A Wildman Follow us on Twitter! http://twitter.com/acsCOMPprog From owner-chemistry@ccl.net Fri Mar 14 15:34:00 2014 From: "Mauricio Federico Erben erben##quimica.unlp.edu.ar" To: CCL Subject: CCL: Sensitivity of vertical ionization energy and homo on geometry Message-Id: <-49852-140314141810-3382-4uPjc7eEDbVpXaqBgAn7tw~~server.ccl.net> X-Original-From: "Mauricio Federico Erben" Content-Transfer-Encoding: 8bit Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Date: Fri, 14 Mar 2014 15:17:47 -0300 MIME-Version: 1.0 Sent to CCL by: "Mauricio Federico Erben" [erben,,quimica.unlp.edu.ar] Dear all, Interesting investigations on the relationship between conformational properties and ionization energies have been reported by the Deleuze´s group, including both experimental and theoretical aspects. I would like to recommend the following articles on this topic (the list is not exhaustive): J. Am. Chem. Soc. 2001, 123, 4049-4061. J. Chem. Phys. 2006, 125, 104309. J. Phys. Chem. A 2010, 114, 4400-4417. Some time ago, we investigated the dependence of the homo with the S-S torsion angle for a series of related disulfide and trisulfide species, please also see: Inorg. Chem. 2002, 41, 3740. In my opinion, the subject posted is interesting since the current resolutions achieved by modern photoelectron spectroscopy techniques allow for analyzing the conformational properties and its effects on ionization processes including both the fundamental as well as ionized states. Best wishes, Mauricio. ----- Original Message ----- > From: Scott McKechnie jsm78---cam.ac.uk To: Erben, Mauricio Federico Sent: Thursday, March 13, 2014 3:32 PM Subject: CCL: Sensitivity of vertical ionization energy and homo on geometry Dear Tobias, Many thanks, I realise that my question was a little vague but this is exactly the type of answer I was looking for. The dependence on torsion angle is a nice example and for anyone who is interested he following papers were very helpful: http://dx.doi.org/10.1103/PhysRevB.54.2381 http://dx.doi.org/10.1063/1.449450 I'd welcome any further examples or references but otherwise I'd consider my question solved. In response to the comments about geometric changes that occur during the ionization process, as Dr. Abrash and Dr. Molt correctly pointed out, I am interested in vertical ionization energies where there is no geometric change. Best wishes, Scott On 13 March 2014 09:10, Tobias Schwabe schwabe^^zbh.uni-hamburg.de wrote: Dear Scott, > from my understanding you are also concerned about the effect from the level of theory for geometry optimizations on your ionization energy quality. Unfortunately, I have no reference ready to provide, but in general this cannot be ignored depending on the accuracy you seek. Especially critical, in my opinion, are multiple bond length (e.g. C=O bonds) and aromatic systems. The good news here: the standard recommendations for geometry optimizations also apply here. Depending on system size, go for a hybrid functional (with your favorite dispersion correction) plus a triple zeta quality basis set (my preferences here: B3LYP-D/def2-TZVP or PBE0-D/def2-TZVP). With programs like TURBOMOLE or ORCA, those optimizations can be done routinely on quite large systems. If you are interested in more accurate geometries, use SCS-MP2 or double hybrid functionals, but then you also need a larger set of polarization functions (like def2-TZVPP). In case you cannot afford anything of the aforementioned methods, it's getting harder from my experience. Using a (meta-)GGA functional with RI (= density fitting) yields a 10x speed up (or so) but you should be careful if self-interaction problems might occur in your geometry. For example, I suspect that torsion angles for phenyl rings can be a problem (and might bias your ionization energies). I hope this was helpful to you. Otherwise feel free to ask again. Regards, Tobias