From owner-chemistry -8 at 8- ccl.net Mon Nov 28 00:14:00 2011 From: "Pezhman Zarabadip-Poor pzarabadip~!~gmail.com" To: CCL Subject: CCL: Suitable Basis set for Hg(II) Calculation Message-Id: <-45932-111128000932-13713-Qda366XXAoDy4vYlBWwkIA!A!server.ccl.net> X-Original-From: "Pezhman Zarabadip-Poor" Content-Language: en-us Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii" Date: Mon, 28 Nov 2011 08:39:13 +0330 MIME-Version: 1.0 Sent to CCL by: "Pezhman Zarabadip-Poor" [pzarabadip ~ gmail.com] Dear Ted, I have not employed mentioned Stuttgart basis sets yet. I think I should try them and evaluate the results. Until now I used LANL2DZ, aug-cc-pVDZ--->QZ, and def2-TZVP basis sets. The starting point of these calculations is based on a published paper in which the authors used LANL2DZ for Hg(II) ions and claimed that these ions coordinate to two oxygen atoms of sulfonic acid groups of the main molecule. According to the nature of this interaction which is electrostatic one between Hg(2+) and one negatively charged oxygen I guessed that maybe this proposed structure is not correct. Then, I checked the structure with other basis sets and obtained the structure which I expected (Hg(2+) is in interaction with one oxygen atom on each sulfonic acid group). Then, I came to this point that is my guess and consequent conclusion is correct or the used basis set was not suitable for this system and brought me to a expected point but on a wrong way?! I think maybe I should try LANL2TZ and check the results too?! Best regards, Pezhman -----Original Message----- > From: owner-chemistry+pzarabadip==gmail.com%%ccl.net [mailto:owner-chemistry+pzarabadip==gmail.com%%ccl.net] On Behalf Of Theodore S. Dibble tsdibble*o*esf.edu Sent: Monday, November 28, 2011 5:42 AM To: Zarabadi-Poor, Pezhman Subject: CCL: Suitable Basis set for Hg(II) Calculation Sent to CCL by: "Theodore S. Dibble" [tsdibble##esf.edu] Pezhman, In general, one expects the LANL2DZ basis set is far surpassed by the Stuttgart basis sets, available at http://www.theochem.uni-stuttgart.de/pseudopotentials/index.en.html. This site provides ECPs and matching correlation-consistent basis sets for the outer electrons. It is certainly possible that LANL2DZ actually performs better than more recent basis sets for certain classes of problems. Are there experimental data sets you can use to validate your methods? Best wishes, Ted Dibble Theodore S. Dibble Professor of Chemistry SUNY-Environmental Science and Forestry 1 Forestry Drive Syracuse, NY 13210 (315) 470-6596 (315) 470-6856 (fax) http://www.esf.edu/chemistry/faculty/dibble.htm > "Pezhman Zarabadi-Poor pzarabadip]~[gmail.com" wrote: > > Sent to CCL by: "Pezhman Zarabadi-Poor" [pzarabadip/a\gmail.com] > Dear CCL users, > > I am planning to do some DFT and TDDFT calculations on a complex of Hg(II) and > a naphthalene sulfonic acid derivative. I searched through the literature and > found that some of previous computational works have employed ECP-LANL2DZ for > Hg(II). Is it a good suggestion for doing such calculations? I checked the > larger basis sets such as aug-cc-pVDZ to QZ but I obtained a little bit > different results than the published ones? According to the consultant with an > expert person, there is guess that maybe employing larger basis sets makes Hg > ions too soft and makes the results wrong! > > Your suggestions about the appropriate method/basis sets are highly > appreciated. > > Best regards, > Pezhman Zarabadi-Poorhttp://www.ccl.net/cgi-bin/ccl/send_ccl_messagehttp://www.ccl.net/chemistry/sub_unsub.shtmlhttp://www.ccl.net/spammers.txt