*Work supported by the National Science Foundation. ~Alfred P. Sloan Fellows. J. Lebowitz and P. Resibois, Phys. Rev. 139, A1101 (1965), and references cited therein. H. Mori, Progr. Theoret. Phys. (Kyoto) 33, 423 (1965). 3P. Mazur and I. Oppenheim, J. Phys. Soc. Japan Suppl. 26, 35 (1969) ~ R. J. Rubin, Phys. Rev. 131, 964 (1963). Professor Zwanzig has studied (unpublished notes) Rubin's model...

Date The final copy of this thesis has been examined by the signatories, and we find that both the content and the form meet acceptable presentation standards of scholarly work in the above mentioned discipline. The recent developments of high repetition rate and high average power ultrafast laser open the door for probing molecular structure and dynamics with intense laser fields. In this regi...

How energy moves around between the vibrational modes of a polyatomic molecule is of considerable interest, both spectroscopically and theoretically. Historically the most widely known studies of intramolecular vibrational energy redistribution are associated with thermal unimolecular reactions [1], In the developing unimolecular reaction rate theory, Slater [2] described the excited molecule a...

One could expect to find a simple yet rigorous treatment of anisotropics of polyatomic ions in treatises on structural and inorganic chemistry. However, despite many discussions [1-4] of sizes, shapes and anisotropics of interactions, a unified approach to these anisotropics is, to the authors ' knowledge, conspicuous by its absence from the chemical literature. In fact, desirability of such an...

A four-dimensional intermolecular potential-energy surface has been calculated for the HCN-HCl complex, with the use of the coupled cluster method with single and double excitations and noniterative inclusion of triples. Data for more than 13,000 geometries were represented by an angular expansion in terms of coupled spherical harmonics; the dependence of the expansion coefficients on the inter...

We consider the Bathnagar–Gross–Krook (BGK) model, an approximation of Boltzmann equation, describing time evolution a single momoatomic rarefied gas and satisfying same two main properties (conservation entropy inequality). However, in practical applications, one often has to deal with additional physical issues. First, does not consist only species, but it consists mixture different species. ...

Vibronic radiationless transitions in large polyatomic molecules can be thought of as a process whereby the molecule, initially prepared in a discrete quasistationary state, makes a transition to an adjoining vibronic continuum belonging to a lower electronic state of the same multiplicity. In many instances the transition is analogous to penetration through a barrier between two "nested" poten...

Coupling between Standard Model particles and theoretically well-motivated ultralight dark matter (UDM) candidates can lead to time variation of fundamental constants including the proton-to-electron mass ratio $\mu\equiv m_{p}/m_{e}\approx1836$. The presence nearly-degenerate vibrational energy levels different character in polyatomic molecules result significantly enhanced relative shifts mol...

Time-dependent Hartree-Fock theory has been used to study of the electronic optical response of a series of linear polyenes in strong laser fields. Ethylene, butadiene, and hexatriene have been calculated with 6-31G(d,p) in the presence of a field corresponding to 8.75 x 10(13) W/cm2 and 760 nm. Time evolution of the electron population indicates not only the pi electrons, but also lower lying ...

FERM3D is a three-dimensional finite element program, for the elastic scattering of a low energy electron from a general polyatomic molecule, which is converted to a potential scattering problem. The code is based on tricubic polynomials in spherical coordinates. The electron-molecule interaction is treated as a sum of three terms: electrostatic, exchange. and polarisation. The electrostatic te...