Search results for "atomistic"
showing 6 items of 6 documents
Atomistic modeling of crystal structure of Ca1.67SiHx
2015
The atomic structure of calcium-silicate-hydrate (C-1.67-S-H-x) has been investigated by theoretical methods in order to establish a better insight into its structure. Three models for C-S-H all derived from tobermorite are proposed and a large number of structures were created within each model by making a random distribution of silica oligomers of different size within each structure. These structures were subjected to structural relaxation by geometry optimization and molecular dynamics steps. That resulted in a set of energies within each model. Despite an energy distribution between individual structures within each model, significant energy differences are observed between the three m…
Visualization in the integrated SimPhoNy multiscale simulation framework
2018
Abstract We describe three distinct approaches to visualization for multiscale materials modelling research. These have been developed with the framework of the SimPhoNy FP7 EU-project, and complement each other in their requirements and possibilities. All have been integrated via wrappers to one or more of the simulation approaches within the SimPhoNy project. In this manuscript we describe and contrast their features. Together they cover visualization needs from electronic to macroscopic scales and are suited to simulations made on personal computers, workstations or advanced High Performance parallel computers. Examples as well as recommendations for future calculations are presented.
A method for structure prediction of metal-ligand interfaces of hybrid nanoparticles
2019
Hybrid metal nanoparticles, consisting of a nano-crystalline metal core and a protecting shell of organic ligand molecules, have applications in diverse areas such as biolabeling, catalysis, nanomedicine, and solar energy. Despite a rapidly growing database of experimentally determined atom-precise nanoparticle structures and their properties, there has been no successful, systematic way to predict the atomistic structure of the metal-ligand interface. Here, we devise and validate a general method to predict the structure of the metal-ligand interface of ligand-stabilized gold and silver nanoparticles, based on information about local chemical environments of atoms in experimental data. In …
Understanding Structure and Stability of Monoclinic Zirconia Surfaces from First-Principles Calculations
2017
Under the water-rich pre-treatment and/or reaction conditions, structure and chemistry of the monoclinic zirconia surfaces are strongly influenced by oxygen vacancies and incorporated water. Here, we report a combined first-principles and atomistic thermodynamics study on the structure and stability of selected surfaces of the monoclinic zirconia. Our results indicate that among the studied surfaces, the most stable (111) surface is the least vulnerable towards oxygen vacancies in contrast to the less stable (011) and (101) surfaces, where formation of oxygen vacancies is energetically more favorable. Furthermore, we present a vigorous, systematic screening of water incorporation onto the s…
Multi-scale dynamics simulations of molecular polaritons: The effect of multiple cavity modes on polariton relaxation
2021
It is included two versions of this item: the Accepted Version which is already Open Access and the Published Version which is under an embargo period till 2022-03-09.
Revised Atomistic Models of the Crystal Structure of C–S–H with high C/S Ratio
2016
Abstract The atomic structure of calcium-silicate-hydrate (C1.67–S–H x ) has been studied. Atomistic C–S–H models suggested in our previous study have been revised in order to perform a direct comparison of energetic stability of the different structures. An extensive set of periodic structures of C–S–H with variation of water content was created, and then optimized using molecular dynamics with reactive force field ReaxFF and quantum chemical semiempirical method PM6. All models show organization of water molecules inside the structure of C–S–H. The new geometries of C–S–H, reported in this paper, show lower relative energy with respect to the geometries from the original definition of C–S…