Resonance Raman spectra of selected pterin molecules. Genetic algorithms approach to force field scaling
✍ Scribed by B. Brutovský; J. Uličný; P. Miškovský; V. Lisý; L. Chinsky
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 259 KB
- Volume
- 29
- Category
- Article
- ISSN
- 0377-0486
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✦ Synopsis
The resonance Raman spectra of the pterin group molecules lumazine and isoxanthopterin are presented for the Ðrst time and their in-plane normal modes analysis is performed. The semiempirical AM1 force Ðelds of the molecules were scaled using a novel computational approach to the determination of scale factors. The problem of force Ðeld scaling was conceived as a multiparameter optimization task and the adaptive optimization technique Genetic Algorithms (GA) was applied to solve it. The approach permits, owing to the power of GA, the automatic construction of the most reasonable assignment of the calculated normal mode wavenumbers to the experimental bands. Simultaneously, the scale factor values are tuned during the optimization procedure, minimizing the root mean square deviation between the experimental and calculated harmonic normal mode wavenumbers. It was found that the GA-based scaling procedure is efficient enough to recover the principal vibrational modes.