scholarly journals Halogenated Anthracenes as Building Blocks for the On-Surface Synthesis of Covalent Polymers: Structure Prediction with the Lattice Monte Carlo Method

2021 ◽  
Author(s):  
Jakub Lisiecki ◽  
Paweł Szabelski
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Structure Prediction ◽  
Building Blocks ◽  
Lattice Monte Carlo

scholarly journals Calculations of the Effective Thermal Conductivity in a Model of Syntactic Metallic Hollow Sphere Structures Using a Lattice Monte Carlo Method

2008 ◽  
Vol 273-276 ◽  
pp. 216-221 ◽  
Author(s):  
Thomas Fiedler ◽  
Andreas Öchsner ◽  
Irina V. Belova ◽  
Graeme E. Murch
Keyword(s):  
Thermal Conductivity ◽  
Monte Carlo ◽  
Monte Carlo Method ◽  
Effective Thermal Conductivity ◽  
Hollow Sphere ◽  
Cutting Planes ◽  
Two Dimensional ◽  
Adhesively Bonded ◽  
Lattice Monte Carlo ◽  
The Matrix

In this paper, a Lattice Monte Carlo method is used to determine the effective thermal conductivity in two dimensional models of adhesively bonded metallic hollow sphere structures (MHSS). In contrast to earlier approaches, more realistic distributions of spheres without the simplification of cubic symmetric arrangements are considered in this study. For the Monte Carlo analyses, two-dimensional periodic lattices representing different cutting planes through MHSS are generated. Therefore, an algorithm is used which sequentially fills the lattice by adding cut spherical shells and inclusions in the matrix. Another focus of this work is the analysis of the influence of different geometric circle distributions on the effective thermal conductivity. The findings of the random arrangements are also compared to a regular primitive cubic arrangement and with a Maxwell-type approach.

scholarly journals Impurity lattice Monte Carlo for hypernuclei

2020 ◽  
Vol 56 (10) ◽  
Author(s):  
Dillon Frame ◽  
Timo A. Lähde ◽  
Dean Lee ◽  
Ulf-G. Meißner
Keyword(s):  
Field Theory ◽  
Monte Carlo ◽  
Monte Carlo Method ◽  
Effective Field Theory ◽  
Computational Effort ◽  
Effective Field ◽  
Binding Energies ◽  
Chiral Effective Field Theory ◽  
Lattice Monte Carlo ◽  
Nucleon Interactions

AbstractWe consider the problem of including $$\varLambda $$ Λ hyperons into the ab initio framework of nuclear lattice effective field theory. In order to avoid large sign oscillations in Monte Carlo simulations, we make use of the fact that the number of hyperons is typically small compared to the number of nucleons in the hypernuclei of interest. This allows us to use the impurity lattice Monte Carlo method, where the minority species of fermions in the full nuclear Hamiltonian is integrated out and treated as a worldline in Euclidean projection time. The majority fermions (nucleons) are treated as explicit degrees of freedom, with their mutual interactions described by auxiliary fields. This is the first application of the impurity lattice Monte Carlo method to systems where the majority particles are interacting. Here, we show how the impurity Monte Carlo method can be applied to compute the binding energies of the light hypernuclei. In this exploratory work we use spin-independent nucleon–nucleon and hyperon–nucleon interactions to test the computational power of the method. We find that the computational effort scales approximately linearly in the number of nucleons. The results are very promising for future studies of larger hypernuclear systems using chiral effective field theory and realistic hyperon–nucleon interactions, as well as applications to other quantum many-body systems.

Lattice Monte Carlo Simulations of Vacancy-Mediated Diffusion and Aggregation using Ab-Initio Parameters

1997 ◽  
Vol 469 ◽  
Author(s):  
Marius M. Bunea ◽  
Scott T. Dunham
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Nearest Neighbor ◽  
First Principle ◽  
High Concentration ◽  
Lattice Monte Carlo ◽  
First Principle Calculations ◽  
System Energy ◽  
Concentration Diffusion ◽  
Nearest Neighbor Distances

The lattice Monte Carlo method with parameters from recent first-principle calculations1,2 are used to investigate dopant diffusion in silicon. In the simulations, vacancy hopping on a silicon lattice is biased by changes in system energy, including interactions up to the sixth-nearest neighbor. We find that vacancy-mediated diffusivity increases dramatically above 1020 cm−3, in agreement with experimental observations3 and previous calculations.4 However, for very long simulation times, arsenic diffusivity is reduced due to formation of AsxV complexes, with clustering more pronounced at high doping levels. As suggested by Ramamoorthy and Pantelides,5 we find that As2V complexes are mobile, and although they diffuse much more slowly than AsV pairs, they appear likely to have a significant role in high concentration diffusion due to their much higher numbers. We also investigated dopant fluxes in a vacancy gradient. For dopants like As for which pair diffusion is limited by the dissociation to third-nearest neighbor distances, the dopant flux is less than that predicted by pair diffusion models, with greater difference at higher temperatures. In contrast, for phosphorus/vacancy pairs, whose diffusion is limited by dopant/vacancy exchange, the dopant flux is close to the predictions of pair diffusion.

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