Молекулярная спектроскопия Молекулярная спектроскопия
Guest | Паспорт
 Rus | Eng   
Словарь  |  Помощь

Институт прикладной физики РАН


   Dr. Group leader Oleg Lvovich Polyansky, 
Institute of Applied Physics Russian Academy of Sciences, Laboratory of Microwave Spectroscopy


   Dr. Nikolay F.Zobov,
Institute of Applied Physics Russian Academy of Sciences, Laboratory of Microwave Spectroscopy


   Sergey V. Shirin, 
Institute of Applied Physics Russian Academy of Sciences, Laboratory of Microwave Spectroscopy

The team from Microwave Spectroscopy Laboratory of Institute of Applied Physics Russian Academy of Sciences (IAP) has long and successful history in studying light molecules. First theoretical works studying water spectrum were published in early 80-s. Originally the analysis was done using effective Hamiltonians. Leader of the theoretical group of the laboratory O.L. Polyansky in 1985 proposed Pade- Borel method of series summation since then widely used for studying water and related molecules spectra. Since early 90-s progress in computational hardware and ‘software’ lead to variational calculations taking the bigger part in analyzing triatomic molecules spectra. In particular the program suit DVR3D for variational calculations of vibration-rotation energy levels using the exact kinetic energy operator for nuclear motion was developed in the group of Prof. J. Tennyson University College London. This development had given start to very successful cooperation between IAP RAS and UCL. The UK being experts in the variational calculations with Russian side being experts in analysis of complicated experimental spectra. During the last 7 years tens of thousands transitions of water were analyzed and assigned in broad frequency range from far IR to near UV, the most known being study of sun sport spectrum, published in ‘Science’. The accuracy of variational calculations is mostly determined by the quality of used potential energy surface (PES). The team took part in development of several semiemperical PESes for H2O and H2S which were the best at the time. In recent years ab initio PESes are stating to play the leading role in improving accuracy of calculations. It’s also important to take into consideration corrections to Born- Oppenheimer surface. Members of the team actively worked in all these fields leading to publication in ‘Science’ describing the methodology of obtaining ab initio PES of water which gives energy levels with standard deviation 1 cm-1. In Microwave Spectroscopy Laboratory each member of the team poses a computer (including 2 Pentium IV computers) with quick Internet connection. They also have accounts and disk space on UCL cluster of computers (about 10 Pentium IV PCs and Ra: a cluster of four Sun Microsystems V880 server, each V880 contains 8 processors and 16GB of memory).

In summation: members of IAP RAS team are experts in analysis of complicated experimental spectra, development of ab initio methods, PES optimization by fitting to observed vibration-rotation energy levels. Their expertise is confirmed by about 50 publications on studying water and related molecules spectra. They complement other teams’ strong sides making the completion of their parts of the proposal beyond any doubt.

List of publications
1 O.L.Polyansky, A.G.Csaszar, S.V.Shirin, N.F.Zobov, P.Barletta, J.Tennyson, D.W.Schwenke, P.J.Knowles, High accuracy ab initio rotation-vibration transitions of water, Science, 299, 539-542 (2003).
2 A.Callegari, P.Theule, R.N.Tolchenov, N.F.Zobov, O.L.Polyansky, J.Tennyson, J.S.Muenter, T.R.Rizzo, Dipole moments of highly vibrationally excited water, Science, 297, 993-995 (2002).
3 O.L.Polyansky, N.F.Zobov, S.Viti, J.Tennyson, P.F.Bernath, L.Wallace, Water in the Sun: line assignments based on variational calculations, Science, 277, 346-349 (1997).
4 S.V.Shirin, O.L.Polyansky, N.F.Zobov, P.Barletta, J.Tennyson, Spectroscopically determined potential energy surface of H2-16O up to 25000 cm-1, Journal of Chemical Physics, 118, 2124-2129 (2003).
5 S.V.Shirin, N.F.Zobov, A.V.Savin, O.L.Polyansky, Automated technique for identifying experimental vibrational-rotational molecular spectra based on variational calculations, Radiophysics and Quantum Electronics, 44, 878-884, (2001).

Грант INTAS 00-189