Numerical Initial Value Problems in Ordinary Differential Equations

In the mid-1970s, surface-enhanced Raman scattering (SERS) was discovered which impacted on surface science and spectroscopy because of its extremely high surface sensitivity. However, SERS had not developed as many people had hoped to be a powerful surface diagnostic technique that can be widely used because of some obstacles. For example, only three noble metals Au, Ag, and Cu could provide large enhancement, severely limiting the widespread applications involving other metallic materials of both fundamental and practical importance. In this article, emphasis is put on the recent work of our group to directly generate SERS on net transition metals (e.g., Pt, Ru, Rh, Pd, Fe, Co, Ni, and their alloys) by developing various roughening procedures and optimizing the performance of the confocal Raman microscope. An approach of replacing the randomly roughened surface with ordered nanorod arrays of transition metals is introduced as a promising class of highly SERS-active substrates. The surface enhancement fa...

Surface-Enhanced Raman Scattering: From Noble to Transition Metals and from Rough Surfaces to Ordered Nanostructures

Introduction to Surface Chemistry and Catalysis

A review of the theoretical and computational modeling of bimolecular reactions is given. The review is divided into several sections which are as follows: gas-phase thermal reactions; gas-phase state-selected reactions and product state distributions; and condensed-phase bimolecular reactions. The section on gas-phase thermal reactions covers the enthalpies and free energies of reaction, kinetics, saddle points and potential energy surfaces, rate theory for simple barrier reactions and bimolecular reactions over potential wells. The section on gas-phase state-selected reactions focuses on electronically adiabatic reactions and electronically nonadiabatic reactions. Finally, the section on condensed-phase bimolecular reactions covers reactions in liquids, reactions on surfaces and in solids and tunneling at low temperature.

Modeling the Kinetics of Bimolecular Reactions

Theories of intramolecular vibrational energy transfer

Using the WKB semiclassical approximation, the dependence of the probability of vibrational de‐excittion on the assumed form of the interaction potential is discussed The asymptotic results show that the Morse and Lennard‐Jones potentials have, respectively, two and three correction terms in the exponential part The magnitudes of the correction terms are important compared to the leading term The exact form of the leading term is also dependent upon the interaction potential

Dependence of the Probabilities of Vibrational De‐Excitation on Interaction Potentials

Vibration-rotation-translation energy transfer in HF-HF and DF-DF

An analytic approach is presented for the calculation of vibration‐to‐vibration (VV) energy transfer in near‐resonant systems and is applied to several collision systems over the temperature range of 300–4000°K with particular emphasis on N2+CO collisions. Calculated values of VV probabilities for CO+N2 and CO+NO are in good agreement with experimental data. For CO+O2 and CO+D2, calculated probabilities are larger than high temperature experimental data by factors of 3 to 5. For all systems, including NO+N2, the calculated result at low temperatures (≃300°K) is in reasonable agreement with experiment. It is also shown that the VV probability for CO+N2 is very large compared with the VT probability for N2(v=1)+CO → N2(v=0)+CO at lower temperatures.

Vibration-to-vibration energy transfer in near-resonant collisions

Formation of vibrationally excited hydrogen molecules on a graphite surface

Vibrational energy transfer is discussed for a Lennard‐Jones intermolecular interaction energy by use of the WKB semiclassical wavefunctions, from the point of view of the effect of an attractive term in the interaction energy. The effect is found to be very important in controlling the over‐all magnitude of the de‐excitation probability per unit time. An expression for fitting a Lennard‐Jones potential to an exponential potential is derived by comparing the leading terms in the exponent of the perturbation integral.

Hyung Kyu Shin

Papers

Dependence of the Probabilities of Vibrational De‐Excitation on Interaction Potentials

Vibration-rotation-translation energy transfer in HF-HF and DF-DF

Vibration-to-vibration energy transfer in near-resonant collisions

Formation of vibrationally excited hydrogen molecules on a graphite surface

Inelastic Molecular Collisions with a Lennard‐Jones (12–6) Interaction Energy