Skip to main content
placeholder image

A systematic benchmarking of computational vibrational spectroscopy with DFTB3: Normal mode analysis and fast Fourier transform dipole autocorrelation function

Journal Article


Download full-text (Open Access)

Abstract


  • Computational vibrational spectroscopy serves as an important tool in the interpretation of experimental infrared (IR) spectra. In this article, we present a systematic benchmarking study of DFTB3 with two different computational vibrational spectroscopic methods, based on either normal mode analysis (NMA) or fast Fourier transform dipole autocorrelation function (FT‐DAC). The results were compared with experimental data and theoretical calculations with B3LYP/cc‐pVTZ. The empirical scaling factors for DFTB3/NMA, DFTB3‐freq/NMA, and DFTB3/FT‐DAC methods are 0.9993, 1.0059, and 0.9982, respectively. We also demonstrate the significance of anharmonicity and conformational sampling in vibrational spectroscopic calculations on flexible molecules. As expected, DFTB3/FT‐DAC predicted the anharmonic vibrational peaks more accurately than DFTB3/NMA and NMA spectra are highly dependent on the initial structures. The potential limitations of DFTB3 for vibrational spectroscopic calculations and the challenges in assigning the FT‐DAC spectral peaks were noted. DFTB3/FT‐DAC is expected to serve as a promising technique in computational spectroscopy in complex biomolecular systems.

Authors


  •   Inakollu, Venkatasaisandeep (external author)
  •   Yu, Haibo

Publication Date


  • 2018

Citation


  • Inakollu, V. Sandeep. & Yu, H. (2018). A systematic benchmarking of computational vibrational spectroscopy with DFTB3: Normal mode analysis and fast Fourier transform dipole autocorrelation function. Journal of Computational Chemistry, 39 (25), 2067-2078.

Ro Full-text Url


  • https://ro.uow.edu.au/cgi/viewcontent.cgi?article=2310&context=ihmri

Ro Metadata Url


  • http://ro.uow.edu.au/ihmri/1283

Number Of Pages


  • 11

Start Page


  • 2067

End Page


  • 2078

Volume


  • 39

Issue


  • 25

Place Of Publication


  • United States

Abstract


  • Computational vibrational spectroscopy serves as an important tool in the interpretation of experimental infrared (IR) spectra. In this article, we present a systematic benchmarking study of DFTB3 with two different computational vibrational spectroscopic methods, based on either normal mode analysis (NMA) or fast Fourier transform dipole autocorrelation function (FT‐DAC). The results were compared with experimental data and theoretical calculations with B3LYP/cc‐pVTZ. The empirical scaling factors for DFTB3/NMA, DFTB3‐freq/NMA, and DFTB3/FT‐DAC methods are 0.9993, 1.0059, and 0.9982, respectively. We also demonstrate the significance of anharmonicity and conformational sampling in vibrational spectroscopic calculations on flexible molecules. As expected, DFTB3/FT‐DAC predicted the anharmonic vibrational peaks more accurately than DFTB3/NMA and NMA spectra are highly dependent on the initial structures. The potential limitations of DFTB3 for vibrational spectroscopic calculations and the challenges in assigning the FT‐DAC spectral peaks were noted. DFTB3/FT‐DAC is expected to serve as a promising technique in computational spectroscopy in complex biomolecular systems.

Authors


  •   Inakollu, Venkatasaisandeep (external author)
  •   Yu, Haibo

Publication Date


  • 2018

Citation


  • Inakollu, V. Sandeep. & Yu, H. (2018). A systematic benchmarking of computational vibrational spectroscopy with DFTB3: Normal mode analysis and fast Fourier transform dipole autocorrelation function. Journal of Computational Chemistry, 39 (25), 2067-2078.

Ro Full-text Url


  • https://ro.uow.edu.au/cgi/viewcontent.cgi?article=2310&context=ihmri

Ro Metadata Url


  • http://ro.uow.edu.au/ihmri/1283

Number Of Pages


  • 11

Start Page


  • 2067

End Page


  • 2078

Volume


  • 39

Issue


  • 25

Place Of Publication


  • United States