The molecular geometry, vibrational frequencies, infrared intensities, Raman scattering activities and several thermodynamic parameters of anilinium nitrate in the ground state have been calculated by both Hartree-Fock (HF) and three density functional theory (DFT) methods (B3LYP, BLYP and B3PW91) using the 6-31G(d) basis set. The results of the optimized molecular structure are presented and c...

The interstellar presence of protonated nitrous oxide has been suspected for some time. Using established high-accuracy quantum chemical techniques, spectroscopic constants and fundamental vibrational frequencies are provided for the lower energy O-protonated isomer of this cation and its deuterated isotopologue. The vibrationally-averaged B0 and C0 rotational constants are within 6 MHz of thei...

Vibrational modes in O-doped GaN have been observed at 544 cm~1 in Raman spectroscopy. Under perturbation of large hydrostatic pressure the mode appears as a set of three di!erent lines Q 123 whose relative intensities change by pressure. A switching between the modes occurs near 10 and 20 GPa and is found to correlate with the electron capture process to the DX-like state of O. We employ a sim...

Optical pulses at THz and mid-infrared frequencies tuned to specific vibrational resonances modulate the lattice along chosen normal mode coordinates. In this way, solids can be switched between competing electronic phases and new states are created. Here, we use vibrational modulation to make electronic interactions (Hubbard-U) in Mott-insulator time dependent. Mid-infrared optical pulses exci...

The FTIR spectra of 4-dimethylamino pyridinium-betaine of squaric acid in 4000–100 cm frequency region in solid state were measured. In addition, the structure and harmonic vibrational frequencies of this molecule were theoretically evaluated using restricted Hartree–Fock and B3LYP density functional methods. The computed vibrational frequencies are used to determine the types of molecular moti...

We present an assessment of different density functionals, with emphasis on range-separated hybrids, for the prediction of fundamental and harmonic vibrational frequencies, infrared intensities, and Raman activities. Additionally, we discuss the basis set convergence of vibrational properties of H2O with long-range corrected hybrids. Our results show that B3LYP is the best functional for predic...

Polyfluorenes reveal a complex interplay between emissive properties and intraand intermolecular structure. Vibrational frequencies and intensities determined by Raman spectroscopy are strongly influenced by variations in the backbone as well as side chain conformations. Changes in the structural and electronic properties of two side group substituted polyfluorenes (PF): ethyl-hexyl substituted...

We determine a model of the ionic interactions in RF3 compounds, where R is a rare-earth element in the series from La to Lu, by an analysis o f data on the bond length and the vibrational mode frequencies of the PrF3, GdF3 and HoF3 molecular monomers. All RF3 monomers are predicted to have a pyramidal shape, displaying a progressive flattening of the molecular shape in parallel with the lantha...

Brushite, CaHPO4·2H2O, is a crystalline hydrated acidic form of calcium phosphate that occurs in both physiological and pathological biomineralization processes. Additionally, it is biocompatible in humans. Several groups have investigated the experimental Fourier transform infrared vibrational spectrum of brushite. These investigations have led to a longstanding debate concerning the correct a...

We have investigated the terahertz (THz) spectrum of 2,4-DNT by using Fourier transform infrared spectroscopy in the 0.2–19.5 THz region. We also examined low-frequency intermolecular or phonon modes between 0.2 and 1.8 THz via THz time-domain spectroscopy. The extracted absorption coefficient and refractive index of an intermolecular band at 1.08 THz are 110 cm 1 and 1.67, respectively. Densit...