CCL: Suitable Basis set for Hg(II) Calculation

 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