Chemists routinely create models of reaction systems to understand reaction mechanisms, kinetic properties, process yields under various operating conditions, or the impact of chemicals on man and the environment. As opposed to concise physical laws, these models are attempts to mimic the system by hypothesizing, extracting, and encoding system features (e.g. a potentially relevant reaction pat...

We apply recently developed techniques for pattern recognition to construct a generative model for chemical structure. This approach can be viewed as ligand-based de novo design. We construct a statistical model describing the structural variations present in a set of molecules which may be sampled to generate new structurally similar examples. We prevent the possibility of generating chemicall...

We discuss recent models of chemical evolution in the developing and collapsing protostellar envelopes associated with low-mass star formation. In particular, the effects of depletion of gas-phase molecules onto grain surfaces is considered. We show that during the middle to late evolutionary stages, prior to the formation of a protostar, various species selectively deplete from the gas phase. ...

Emissions from fossil fuel combustion pose a serious threat to public health and =pose the need for animproved monitoring of polycyclic aromatic hydrocarbons (PARS), a major class of persistent organicpollutants. For this purpose the present study reports an investigation of the electronic structure of Pyrene byuse of different chemical models We also made a comparison between different chemica...

A review is given on actual numerical models for CVD equipment and processes. While the basic work concerning the differential equations and the boundary conditions has been established already a decade or more ago, the more recent availability of increased computing power has enabled simulation to become a predictive tool in equipment and process design. The present task in CVD simulation incl...

The origin of the anomeric effect has remained an open question. After Mo demonstrated that hyperconjugation is not responsible for the anomeric effect [Y. Mo, Nature Chem., 2010, 2, 666.], electrostatic interactions and Pauli repulsions have been at the center of this debate. In this work, the total energies of the most stable rotamers of the equatorial and axial anomers of fluoro, hydroxyl, c...

In this review we re-evaluate our observational and theoretical understanding of the chemical evolution of protoplanetary disks. We discuss how improved observational capabilities have enabled the detection of numerous molecules exposing an active disk chemistry that appears to be in disequilibrium. We outline the primary facets of static and dynamical theoretical chemical models. Such models h...