Intrinsic anharmonicities in theBX42−orthorhombic sublattice

On anharmonicities of giant dipole excitations

The role of anharmonic effects on the excitation of the double giant dipole resonance is investigated in a simple macroscopic model. Perturbation theory is used to find energies and wavefunctions of the anharmonic oscillator. The cross sections for the electromagnetic excitation of the oneand two-phonon giant dipole resonances in energetic heavy ion collisions are then evaluated through a semic...

Vibrational Anharmonicities and Reactivity of Tetrafluoroethylene

Compared to ethylene and its nonfluorinated derivatives, C(2)F(4) is peculiar in many reactions. It very easily adds to radicals and prefers formation of four-membered rings over Diels-Alder reactions. This has been rationalized by the preference of fluorine for carbon sp(3) hybridization, which is possible on opening of the double bond. Another property, the thermal dissociation of the C ═ C b...

On sublattice determinants in reduced bases

Lenstra, Lenstra, and Lovász in [7] proved several inequalities showing that the vectors in an LLL-reduced basis are short, and near orthogonal. Here we present generalizations, from which with k = 1, and k = n we can recover their inequalities: Theorem 1. Let b1, . . . , bn ∈ R be an LLL-reduced basis of the lattice L, and d1, . . . , dk arbitrary linearly independent vectors in L. Then ‖b1 ‖ ...

Suppression of anharmonicities in crystalline membranes by external strain

Correction and Addition to “Vibrational Anharmonicities and Reactivity of Tetrafluoroethylene”

Due to a misunderstanding in the proof corrections, many calculated anharmonicities in Table 2 cannot be distinguished from the spectroscopic ones. This table is therefore reproduced here once more. In the meantime, we were able to calculate at the same level (MP2/cc-pVTZ) as the anharmonicities the Fermi resonance terms (interaction matrix elements between the levels) that were derived from th...