Dynamics of Molecular Crystals and Adsorbed Molecular Layers (Including Analytical Potential Expansions)

摘要

The subject of the thesis is: lattice dynamics calculations on molecular crystals and physically adsorbed molecular layers. The methods used are the standard harmonic method for the solids with larger molecules (chlorinated benzenes and tetracyanoethyene) and the Time-Dependent Hartree (TDH) method for N2, H2 and D2 crystals and overlayers. The harmonic method is extended to include the coupled intramolecular vibrations (vibrons). In the quantum mechanical TDH method the translational vibrations of the molecules (phonons) are expanded in a basis of three-dimensional harmonic oscillator wave functions and their collective librations (librons) or hindered rotations (rotons) in a free rotor basis. For the larger molecules the authors have used semi-empirical atom-atom potentials, for H2, D2 and N2 they have based themselves on ab initio intermolecular potentials, with their anisotropy given explicitly in spherical harmonics.