High performance computing has a great potential to provide a range of significant benefits for investigating biological systems. These systems often present large modelling problems with many coupled subsystems, such as when studying colonies of bacteria cells. The aim to understand cell colonies has generated substantial interest as they can have strong economic and societal impacts through their roles in in industrial bioreactors and complex community structures, called biofilms, found in clinical settings.
View Article and Find Full Text PDFThis paper describes a formalism for extracting spatially varying transport coefficients from simulations of a molecular fluid in a nanochannel. This approach is applied to self-diffusion of a Lennard-Jones fluid confined between two parallel surfaces. A numerical grid is laid over the domain confining the fluid, and fluid properties are projected onto the grid cells.
View Article and Find Full Text PDFOne of the most significant challenges faced by hydrogeologic modelers is the disparity between the spatial and temporal scales at which fundamental flow, transport, and reaction processes can best be understood and quantified (e.g., microscopic to pore scales and seconds to days) and at which practical model predictions are needed (e.
View Article and Find Full Text PDFActivation energies for water cluster evaporation are of interest in many areas of chemical physics. We present the first computation of activation energies for monomer evaporation of small water clusters using the formalism of dynamical nucleation theory (DNT). To this end, individual evaporation rate constants are computed for water clusters (H(2)O)(i), where i=2-10 for temperatures ranging from 243 to 333 K.
View Article and Find Full Text PDFWe report here that molecular self-assembly can effectively direct and enhance specific reaction pathways. Using perylene pi-pi stacking weak attractive forces, we succeeded in synthesizing perylene bisimide macrocyclic dimer and a concatenated dimer-dimer ring from dynamic self-assembly of monomeric bis-N,N'-(2-(2-(2-(2-thioacetylethoxy)ethoxy)ethoxy)ethyl)perylenetetracarboxylic diimide. The monocyclic ring closure and the dimer-dimer ring concatenation were accomplished through formation of disulfide bonds, which was readily triggered by air oxidization under basic deacetylation conditions.
View Article and Find Full Text PDFWe describe the integration and use of the Amica software package ("Atoms & Molecules In Chemical Accuracy") within the Extensible Computational Chemistry Environment (Ecce). Amica is capable of accurately solving the electronic Schrodinger equation of small atoms and molecules using terms that are linear in the interelectronic distances, r(12), on multireference level of theory, but it requires expert knowledge to configure and execute its algorithms. Ecce is a comprehensive suite of tools that support the computational chemistry research processes of computation setup, execution, and analysis through a convenient graphical user interface.
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