We report the experimental observation of intrinsic dynamically localized vibrational states in crystals of the highly nonlinear halide-bridged mixed-valence transition metal complex $\{\left[\mathrm{Pt}\right(\mathrm{en}{)}_2\left]\right[\mathrm{Pt}\left(\mathrm{en}{)}_2{\mathrm{Cl}}_2\right]({\mathrm{ClO}}_4{)}_4\}$, where $\mathrm{en}=\mathrm{ethylenediamine}$. These states are identified by the distinctive structure and strong redshifts they impose upon the overtone resonance Raman spectra. Quantitative modeling of the observed redshifts is presented based on a nonadiabatic coupled electron-lattice model that self-consistently predicts strong nonlinearity and highly localized multiquanta bound states.

In recent years there has been growing interest in the use of plasma technology for CO ₂ conversion. To improve this application, a good insight into the underlying mechanisms is of great importance. This can be obtained from modeling the detailed plasma chemistry in order to understand the chemical reaction pathways leading to CO ₂ conversion (either in pure form or mixed with another gas). Moreover, in practice, several plasma reactor types are being investigated for CO ₂ conversion, so in addition it is essential to be able to model these reactor geometries so that their design can be improved, and the most energy efficient CO ₂ conversion can be achieved. Modeling the detailed plasma chemistry of CO ₂ conversion in complex reactors is, however, very time-consuming. This problem can be overcome by using a combination of two different types of model: 0D chemical reaction kinetics models are very suitable for describing the detailed plasma chemistry, while the characteristic features of different reactor geometries can be studied by 2D or 3D fluid models. In the first instance the latter can be developed in argon or helium with a simple chemistry to limit the calculation time; however, the ultimate aim is to implement the more complex CO ₂ chemistry in these models. In the present paper, examples will be given of both the 0D plasma chemistry models and the 2D and 3D fluid models for the most common plasma reactors used for CO ₂ conversion in order to emphasize the complementarity of both approaches. Furthermore, based on the modeling insights, the paper discusses the possibilities and limitations of plasma-based CO ₂ conversion in different types of plasma reactors, as well as what is needed to make further progress in this field.