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

Poster session, H8 121Accurate theoretical rotation-vibration spectrum of H 2 CSIakov Polyak 1 , Andrey Yachmenev 2 , Walter Thiel 11 Max-Planck-Institut für Kohlenforschung, Germany, polyak@mpi-muelheim.mpg.de;2 Karlsruher Institut für Technologie, Germany, andrey.yachmenev@chemie.unikarlsruhe.dePolyak I.Yachmenev A.Thiel W.In the current work we present the variationally computed rotation-vibration spectrumof thioformaldehyde (H 2 CS), for which an experimental infrared high-resolution Fouriertransform study was reported by Flaud et al. in 2008. 1 We use the recently published 2accurate ab initio potential energy surface, constructed by pushing the accuracy to thelimit feasible today. The vibrational fundamental wavenumbers as well as 2υ 2 and υ 2 +υ 3term values of H 2 CS obtained from this surface agree with experiment to within 1 cm -1 .Having such a high-level fully ab initio potential surface is of particular importance forH 2 CS due to the shortage of high-resolution spectroscopic data, and hence the limitedpossibility to fit a calculated surface to experimental data. The rovibrational spectrum ofH 2 CS was calculated at T=300 K involving states with energies up to 5000 cm -1 androtational quantum numbers up to J = 20 with the use of the variational programTROVE. 3 The electric dipole moment surface was computed at the coupled cluster levelof theory with the use of an augmented correlation-consistent quadruple-zeta basis set inthe frozen-core approximation.References[1] J.-M. Flaud, W. J. Lafferty, A. Perrin, Y. S. Kim, H. Beckers, and H. Willner, J.Quant. Spectrosc. Radiat. Transf. 109, 995, 2008.[2] A. Yachmenev, S. N. Yurchenko, T. Ribeyre, and W. Thiel, J. Chem. Phys. 135,074302, 2011[3] S. N. Yurchenko, W. Thiel, and P. Jensen, J. Mol. Spectrosc. 245, 126, 2007