Fundamental vibrational frequencies and dominant resonances in methylamine isotopologues by ab initio and density functional theory methods
✍ Scribed by Chen Levi; Jan M. L. Martin; Ilana Bar
- Publisher
- John Wiley and Sons
- Year
- 2008
- Tongue
- English
- Weight
- 116 KB
- Volume
- 29
- Category
- Article
- ISSN
- 0192-8651
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Ab initio and density functional theory (DFT) calculations were performed for obtaining fundamental vibrational frequencies of methylamine, CH~3~NH~2~, and its deuterated variants CH~3~ND~2~, CD~3~NH~2~, and CD~3~ND~2~. The calculations were carried out using the CCSD(T) coupled cluster approximation with cc‐pVTZ and cc‐pVQZ basis sets, and by the DFT method with the semiempirical hybrid functional B97‐1 with polarization consistent pc‐2 and pc‐3 basis sets. Reasonable performance of the DFT harmonic and ab initio harmonic calculations was found, which improved considerably upon combination of the harmonic fundamental frequencies with anharmonic corrections from the smaller, pc‐2, basis. The computed anharmonic fundamental frequencies of methylamine isotopologues agree very well with the experimental values and represent a useful tool for assignment and analysis of the dominant resonances. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008