About 90% of all chemicals are produced with the help of catalysts, substances with the ability to accelerate reactions without being consumed. Metal oxides play a prominent role in catalysis, since they are able to act reversibly in many chemical processes. Zink oxide (ZnO) is used to catalyse a number of industrially important reactions. For many of these reactions water is present as a reactant, product, or byproduct. The surface structure has a significant impact on the catalytic activity. However, currently, no experimental method simultaneously offers the spatial and temporal resolution to directly follow a catalytic process. This thesis explores surface structure dependent dynamical behavior for ZnO surfaces, nanoparticles, and water interfaces, using the computational chemistry method Molecular Dynamics, which enables detailed studies of structural and dynamical processes. Quantum mechanical (QM) calculations have been performed to obtain the energetics of the materials as a function of structure. This data has been used to parametrize reactive force-fields (ReaxFF), since the catalytic processes require both far larger and longer simulations than the capabilities of QM calculations on current computers. The simulations show that when steps are present on the surface, during crystal growth of ZnO, the creation of energetically favorable structures is accelerated. At the ZnO - water interface, structures that favor hydrogen bonding is promoted. At low, monolayer, coverage water adsorbs both molecularly and dissociatively, whereas at high coverage dissociated adsorption is favored. During evaporation from the monolayers, the ratio of dissociated and molecular water is preserved. Surface steps stabilizes the dissociated state as well as increases the rate of dissociation. The dynamical properties of ZnO nanoparticles were explored using Raman measurements and simulation. In both simulation and experiment certain vibrations were suppressed in the nanoparticles, compared to bulk. The simulations show that a narrow surface region lack the bulk-specific vibrations.

This thesis presents a new theoretical formalism which incorporates dynamical effects in atomistic electronic structure and related calculations. This research, fundamental by nature, brings about a deeper understanding of the dynamical processes in a range of materials. This establishes technologically important correlation with experimentally measured macroscopic properties and materials characterization. This method—the first of its kind—is a natural and long overdue extension of customary adiabatically separated time-independent electronic structure methods. It accounts explicitly for atomic motion due to thermal and zero-point vibration. The approach developed requires no direct treatment of time dependence in the quantum mechanical calculations, making the method widely applicable utilizing currently available electronic structure and ab-initio molecular dynamics software. The formalism is extensively applied and demonstrated for the linear optical response of bulk gallium arsenide and electronic structure of the C(111) 2 x 1 surface. Both cases are complimented by comparison of key observables to experimental data which may be used to judge the quality of the results. The results are found to be in good agreement with experimental data, with most exceptions being readily explainable and well understood.

In this thesis, the possible usage of phase change materials in military shelters with the aim of decreasing the heating effect of the solar radiation is presented. In order to meet the rapidly growing demand for energy in military applications, a passive cooling technique, specifically, storing thermal energy with phase change materials is analyzed by using experimental approach. Not only different types of phase change materials but also different amounts of them are examined during the solar loading experiments. In order to simulate solar heat loading on prototype military shelters, solar radiation test or in other words sunshine test that is stated in military standard MIL