We introduce a new Python package (pyHMA) that interfaces with VASP to compute (classical) anharmonic properties of crystalline systems by post-processing data from NVT Born–Oppenheimer ab initio molecular dynamics (AIMD) simulation. It is based on the recently developed harmonically mapped averaging (HMA) method, which leverages analytically known harmonic behavior reformulate direct/conventio...

In this contribution we demonstrate methods for measurement of composition and strain by scanning transmission electron microscopy (STEM). On the one hand, STEM combined with a high angle annular dark field detector allows Z-contrast imaging with high material contrast that can be used for quantification of composition. The suggested method is based on comparison of experiment with image simula...

Carbon nanotubes (CNT) allow easy entrance and passage of water [1] and are thus of interest for microfluidics. In electro-osmosis, charged double layers are set into motion by external electric fields. In recent simulations, electro-osmosis of water inside a CNT in the absence of free charges was observed and rationalized by invoking an electric-field-driven torque-vorticity conversion at orie...

This work is an extension of that performed by Alan, et al. [1, 2], investigating the effect of surface characteristics on the strength of nanoscale silicon (Si) structures. Progress, utilizing CNF, during the 2011/2012 year has been focused in two main areas. We have replicated the process of Alan, et al., to fabricate nanoscale Si beams with current equipment and techniques, and have made pro...

The two main thrusts of computational science are increasingly accurate predictions and faster calculations; to this end, the zeitgeist in molecular dynamics (MD) simulations is pursuing machine learned data driven interatomic models, e.g. neural network potentials, novel hardware architectures, GPUs. Current implementations potentials orders magnitude slower than traditional models while loomi...

There is compelling evidence for the critical role of twin boundaries (TBs) in imparting the extraordinary combination of strength and ductility to nanotwinned metals. Here, we investigate the thermal fluctuations of TBs in face-centered-cubic metals to elucidate the deformation mechanisms governing their kinetic properties using molecular dynamics simulations. Our results show that the TB moti...

We perform large scale three-dimensional molecular dynamics simulations of unlinked and unknotted ring polymers diffusing through a background gel, here a threedimensional cubic lattice. Taking advantage of this architecture, we propose a new method to unambiguously identify and quantify inter-ring threadings (penetrations) and to relate these to the dynamics of the ring polymers. We find that ...

Science fiction aficionados are aware of the prospect a looming technological singularity - hypothetical point in time at which growth becomes uncontrollable and irreversible, resulting unforeseeable changes to human civilization. Basically, once we hit “robots designed improved by robots.” The consequences its potential benefit or harm race have been intensely debated. This is supported realit...