Abstract book - Prof. Per Jensen, Ph.D. - Bergische Universität ...

Poster session, H36 149Test of molecular structure determination on some examplesNatalja Vogt and Jürgen VogtChemical Information Systems, University of Ulm, 89069 Ulm, Germany,natalja.vogt@uni-ulm.deVogt N.Vogt J.The optimization of structural parameters for succinimide, N-methylsuccinimide, maleicanhydride, fumaric acid and the canonical tautomers of thymine and uracil moleculeshas been carried out at the CCSD(T) level of theory in the “frozen core” or “all electroncorrelated” (ae) approximation using triple zeta basis sets. To obtain the “best ab initio”structure, the extrapolation to the higher basis sets was performed using results of MP2calculations. The quality of the theoretical structure calculations was judged bycomparison with microwave (MW) and/or gas-phase electron diffraction (ED) data,transformed to the equilibrium values (r se e ) taking into account harmonic andanharmonic vibrational corrections in the MP2/VTZ approximation, for the followingmolecules: succinimide 1 , N-methylsuccinimide 2 , maleic anhydride 3,4 , fumaric acid 5 ,thymine 6 , and uracil 7 . It is shown that the agreement between the r e (best ab initio) andr se e (ED and/or MW) structural parameters is within the experimental (ED) uncertainties(see Fig.).OOOO0,0150,0100,005C-CC=CO-CC=OC-H0,000re (B3LYP/AVTZ)re (MP2/VTZ)re (MP2/VQZ)re (MP2/wCVQZ)re (MP2 (full)/wCVQZ)re (CCSD(T)/VTZ)Absolute deviations of theoretical and ED bond lengths from r e se (MW) values(in Å) for maleic anhydrideThe project has been supported by the Dr. Barbara Mez-Starck Foundation.References[1] N. Vogt, L.S. Khaikin, O.E. Grikina, N.M. Karasev, J. Vogt, L.V. Vilkov, J. Phys.Chem. A 113 (2009) 931.[2] N.Vogt, Yu.V. Vishnevskiy, A.A. Ivanov, J. Vogt, L.V. Vilkov, Russ. J. Phys.Chem. 82, (2008) 2286.[3] N. Vogt, E.P. Altova, N.M. Karasev, J. Mol. Struct. 978 (2010) 153.[4] N. Vogt, J. Demaison, H.D. Rudolph, Struct. Chem. 22 (2011) 337.[5] N. Vogt, M.A.Abaev, N.M. Karasev, J. Mol. Struct. 987 (2011) 199.[6] N. Vogt, L.S. Khaikin, O.E. Grikina, A.N. Rykov, J. Vogt, L.V. Vilkov, J. Phys.Chem. A 112 (2008) 7662.[7] N. Vogt, L.S.Khaikin, O.E. Grikina, A.N. Rykov et al., to be submitted.re (best ab initio)re se (МW)re se (ED+МW)rs (МW)rg (ED+МW)