Atomistic modeling plays a critical role in advancing our understanding of microstructure evolution and mechanical properties. We present progresses in the theory and computation of ideal strength, dislocations activation processes and brittle fracture from the atomic perspective, in close connection with experiments and other levels of modeling. New discoveries are often made in the “virtual a...

The subband structure of nanowires is commonly obtained through an atomistic tight binding approach. In this work an alternative, continuum based method is investigated, namely a two-band k ·p approximation of the conduction band structure. A derivation of the subband Schrödinger equations from the bulk model and their numerical solution are presented for [100] nanowires. Self-consistent simula...

A powerful way to deal with a complex system is to build a coarse-grained model capable of catching its main physical features, while being computationally affordable. Inevitably, such coarse-grained models introduce a set of phenomenological parameters, which are often not easily deducible from the underlying atomistic system. We present a unique approach to the calculation of these parameters...

We report applications of analytical formalisms and molecular dynamics (MD) simulations to the calculation of redox entropy of plastocyanin metalloprotein in aqueous solution. The goal of our analysis is to establish critical components of the theory required to describe polar solvation at the mesoscopic scale. The analytical techniques include a microscopic formalism based on structure factors...

The objective of the current thesis is to apply atomistic simulation techniques to further the current knowledge of cementitious systems. Hydrated cement is a part of concrete which is one of the most widely used materials in the world. As such the production of cement is responsible for about 5-8% of global CO2 emissions. The optimization of the mechanical properties and durability of concrete...

We explore recent efforts to model the dynamics of sorbed molecules in zeolites with either atomistic methods or lattice models. We discuss the assumptions underlying modern atomistic and lattice approaches, and detail the techniques and applications of modeling both rapid dynamics and activated diffusion. We summarize the major findings discovered over the last several years, and enumerate fut...

This article tries to explain the exceptional levels of knowledge creation in certain industrial clusters, levels that are seemingly higher than what is implied by the usual models of atomistic agents who do not internalize externalities. For this purpose, we introduce reference-dependent utility into an OLG model of an industrial cluster where agents allocate resources between consumption and ...

Machine learning algorithms have been demonstrated to predict atomistic properties approaching the accuracy of quantum chemical calculations at significantly less computational cost. Difficulties arise, however, when attempting to apply these techniques to large systems, or systems possessing excessive conformational freedom. In this article, the machine learning method kriging is applied to pr...

We have carried out atomistic molecular dynamics simulations to study the mechanical properties of cellulose nanofibrils in water and ethanol. The studied elementary fibrils consisted of regions having 34 or 36 cellulose chains whose cross-sectional diameter across the fibril was roughly 3.4 nm. The models used in simulations included both crystalline and non-crystalline regions, where the latt...

Molecular dynamics (MD) methods are opening new opportunities for simulating the fundamental processes of material behavior at the atomistic level. However, current analysis is limited to small domains and increasing the size of the MD domain quickly presents intractable computational demands. A preferred approach to surmount this computational limitation has been to combine continuum mechanics...