Ultrafast two dimensional infrared (2D IR) spectroscopy has been applied to probe the intermolecular vibrational energy exchange between two model molecules, benzonitrile and acetonitrile-(d3). The vibrational energy exchange between these two molecules is manifested through the growth of cross peaks in their 2D IR spectra. In experiments, their nitrile groups (CN) are not involved in the energ...

High resolution anion photodetachment spectra are presented for the methoxide anion and its fully deuterated counterpart. The spectra were obtained with slow electron velocity-map imaging. Improved electron affinities are determined for CH3O as 1.5690+/-0.0019 eV and for CD3O as 1.5546+/-0.0019 eV. The spectra resolve many features associated with spin-orbit and vibronic coupling that were not ...

In this paper we presented a method for determination the lower state energies, and hence the rotational quantum number, in the overtone spectra of methane (the Icosad polyad, between 7076 to 7291 cm). The method explores the temperature dependence of rovibrational transition intensities. In the first part of this report this approach is used with spectra measured at a) 81 K in liquid nitrogen ...

Temperature-dependent terahertz (THz) absorption spectra of poly(3-hydroxyalkanoate)s (PHAs) were measured by using a Fourier transform far-infrared (FT-FIR) spectrometer and a THz time-domain spectrometer over a temperature range of 10 K to 465 K with a liquid helium cryostat and a heating cell. Clear differences were observed between the spectra of crystalline and amorphous polyhydroxybutyrat...

For years, flutists have argued over the tonal advantages of using different precious metals for their instruments. Occasionally, scientists have entered the fray and attempted to offer an objective point of view based on experimental measurements. However, their research often involved actual instruments and performers, ignoring variations in wall thickness, craftsmanship, and human consistenc...

The site and factor group methods of interpreting solid state vibrational spectra are compared. As examples. K2TiF6 (which has one molecular unit in a unit cell) and K2ZrF5 (which has eight in a non-primitive unit cell) are considered. Benzenetricarbonylchromium enables a distinction between site and factor group methods. The modification of the latter needed to account for the spectra of Cr(CO...

It is shown that the density of modes of the vibrational spectrum of globular proteins is universal, i.e. regardless of the protein in question, it closely follows one universal curve. The present study, including 135 proteins analyzed with a full atomic empirical potential (CHARMM22) and using the full complement of all atoms Cartesian degrees of freedom, goes far beyond previous claims of uni...

I review some computational methods for calculating vibrational spectra. They all use iterative eigensolvers to compute eigenvalues of a Hamiltonian matrix by evaluating matrix-vector products (MVPs). A direct-product basis can be used for molecules with five or fewer atoms. This is done by exploiting the structure of the basis and the structure of a direct product quadrature grid. I outline th...

For Klein-Gordon equation a consistent physical interpretation of wave functions is reviewed as based on a proper modification of the scalar product in Hilbert space. Bound states are then studied in a deep-square-well model where spectrum is roughly equidistant and where a fine-tuning of the levels is mediated by PT −symmetric interactions (composed of imaginary delta functions) which mimic cr...

Influence of microscopic inhomogeneity in binary liquid mixtures on their vibrational spectra is studied by doing calculations on a model liquid system. The concentration dependence of the noncoincidence effect (NCE), which is a feature of vibrational bands related to the intermolecular resonant coupling of vibrational modes, is analyzed. It is suggested that observation of convex behavior of t...