From chemistry-request ^at^ www.ccl.net Thu Jan 21 11:07:06 1999 Received: from sg2.csrsrc.mi.cnr.it (sg2.csrsrc.mi.cnr.it [155.253.3.253]) by www.ccl.net (8.8.3/8.8.6/OSC/CCL 1.0) with SMTP id LAA09348 Thu, 21 Jan 1999 11:06:59 -0500 (EST) Received: from localhost by sg2.csrsrc.mi.cnr.it via SMTP (951211.SGI.8.6.12.PATCH1042/951211.SGI.AUTO) for id RAA13626; Thu, 21 Jan 1999 17:13:18 -0800 Date: Thu, 21 Jan 1999 17:13:15 -0800 From: Alessandra Villa To: chemistry #at# www.ccl.net Subject: Summary : ab initio NMR calculation (paramegnetic system) Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII I thank you all the persons that answer me and try to help me I summary the answers (4) , maybe it could be halpfull some someone else. Best Regards Alessandra Questions: > > Dear All, > > I wonder if someone have performed ab initio NMR > shielding tensor calculations on paramagnetic compounds by means of GIAO > or CSGT methods. > Could you point me some paper concerning the argument? or could you > write me your knowledge about the reliability of GIAO and CSGT NMR > shielding tensor calculations on paramagnetic molecules? > I will summary all the answers. > Thank you > > Alessandra Answers: ***************************************************************************** From: "Y. Tantirungrotechai" You might like to ask Dr. K. Ruud who implement GIAO in Dalton. I asked to Dr. K. Ruud, follow his answer From:Kenneth Ruud As far as I know from reading about the NMR of paramagnetic molecules, there are no problem in calculating the NMR parameters of such compounds. There might be important higher-order contributions from e.g.spin-orbit coupling. However, these may aso be calculated with e.g. Dalton. The main problem is normally that programs cannot easily or accurate treat open-shell systems. Dalton should be able to do a fair job on these systems. ***************************************************************************** From: Georg Schreckenbach I have read statements like "truly quantitative calculations of chemical shifts for paramagnetic compounds have not yet been reported" (B=FChl et al., J. Comp. Chem. 1999, 20, 91) whi= ch supports this view. ***************************************************************************** From: Douglas J. Fox Cheeseman, et. al. looked at this when implementing the procedures for Gaussian94. J. Chem. Phys. vol 104, pp 5497 (1996). ***************************************************************************** From:Noah W. Allen, III You might want to check a review article by A.C. de Dios found in the "Journal of Progess in NMR Spectroscopy", 82 (1985) 5035. It's an excellent source of review for this material. ******************************************************************************* Alessandra Villa ale(+ at +)sg2.csrsrc.mi.cnr.it PhD-Student Dipartimento di Chimica Fisica ed Elettrochimica Universtita' degli Studi di Milano via Golgi 19 20133 Milano-Italy *******************************************************************************