title: Simulation of Vibrational Spectra of Large Molecules by Arbitrary Time Propagation.
abstract: Modern ab initio and multiscale methods enable the simulation of vibrational properties of very large molecules. Within the harmonic approximation, the traditional generation of the spectra based on the force field diagonalization can become inefficient due to the excessive demands on computer time and memory. The present study proposes to avoid completely the matrix diagonalization with a direct generation of the spectral shapes. For infrared absorption (IR) and vibrational circular dichroism (VCD) electric and magnetic dipole moments are propagated in a fictitious time and spectral intensities are obtained by Fourier transformation. The algorithm scales quasi-linearly, and for model polypeptide molecules the method was found numerically stable and faithfully reproduced exact transition frequencies and relative intensities.
authors.affiliation: Department of Chemistry, University of Wyoming, 1000 East University Avenue, Laramie, Wyoming 82071, and Institute of Organic Chemistry and Biochemistry, Academy of Sciences, Flemingovo nám. 2, 16610, Praha 6, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Kubelka
authors.affiliation: Department of Chemistry, University of Wyoming, 1000 East University Avenue, Laramie, Wyoming 82071, and Institute of Organic Chemistry and Biochemistry, Academy of Sciences, Flemingovo nám. 2, 16610, Praha 6, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Bouř