Mcfaddenhinson7599

We show that a similar disruption in thermal transport occurs in a single phase system of pure solid atoms as well. We trace the microscopic origin of the anomalous interfacial thermal resistance to a stochastic/frictional forcing-induced alteration in the force autocorrelation function. We propose a simple model consisting of an individual atom impinging in vacuo on a thermostatted solid as a computationally inexpensive alternative for determination of the control parameter range over which thermostat-induced spurious thermal resistance across a solid-liquid interface becomes significant. Our results suggest that the undesirable possibility of MD-deduced temperature jumps being misleading indicators of the interfacial Kapitza resistance could simply be eliminated through a judicious choice of the thermostat control parameter.We propose a novel classical density functional theory (DFT) for inhomogeneous polyatomic liquids based on the grand canonical ensemble of a solute-solvent system. Different from the existing DFT for interaction site model developed by Chandler et al. [J. Chem. Phys. 85, 5971 (1986)], the fundamental quantities in the present theory are the radial density distributions around the atomic site of the solute molecule. With this development and the reference interaction site model equation, we provide self-consistent integral equations for calculating the site-site pair correlation function (PCF) and apply it to the structure of the Lennard-Jones dimer, HCl, and H2O molecular fluids. The site-site PCFs obtained from the new scheme agree well with those from Monte Carlo simulation results.Amorphous alumina (a-AlOx), which plays important roles in several technological fields, shows a wide variation of density and composition. However, their influences on the properties of a-AlOx have rarely been investigated from a theoretical perspective. In this study, high-dimensional neural network potentials were constructed to generate a series of atomic structures of a-AlOx with different densities (2.6 g/cm3-3.3 g/cm3) and O/Al ratios (1.0-1.75). The structural, vibrational, mechanical, and thermal properties of the a-AlOx models were investigated, as well as the Li and Cu diffusion behavior in the models. The results showed that density and composition had different degrees of effects on the different properties. The structural and vibrational properties were strongly affected by composition, whereas the mechanical properties were mainly determined by density. The thermal conductivity was affected by both the density and composition of a-AlOx. However, UNC2250 on the Li and Cu diffusion behavior were relatively unclear.Photocatalytic hydrogenation of carbon dioxide (CO2) to produce value-added chemicals and fuel products is a critical routine to solve environmental issues. However, developing photocatalysts composed of earth-abundant, economic, and environmental-friendly elements is desired and challenging. #link# Metal oxide clusters of subnanometer size have prominent advantages for photocatalysis due to their natural resistance to oxidation as well as tunable electronic and optical properties. Here, we exploit 3d transition metal substitutionally doped Zn12O12 clusters for CO2 hydrogenation under ultraviolet light. By comprehensive ab initio calculations, the effect of the dopant element on the catalytic behavior of Zn12O12 clusters is clearly revealed. The high activity for CO2 hydrogenation originates from the distinct electronic states and charge transfer from transition metal dopants. The key parameters governing the activity and selectivity, including the d orbital center of TM dopants and the energy level of the highest occupied molecular orbital for the doped Zn12O12 clusters, are thoroughly analyzed to establish an explicit electronic structure-activity relationship. These results provide valuable guidelines not only for tailoring the catalytic performance of subnanometer metal oxide clusters at atomic precision but also for rationally designing non-precious metal photocatalysts for CO2 hydrogenation.Many problems in materials science and biology involve particles interacting with strong, short-ranged bonds that can break and form on experimental timescales. Treating such bonds as constraints can significantly speed up sampling their equilibrium distribution, and there are several methods to sample probability distributions subject to fixed constraints. We introduce a Monte Carlo method to handle the case when constraints can break and form. More generally, the method samples a probability distribution on a stratification a collection of manifolds of different dimensions, where the lower-dimensional manifolds lie on the boundaries of the higher-dimensional manifolds. We show several applications of the method in polymer physics, self-assembly of colloids, and volume calculation in high dimensions.Thermal rectification (TR) in graphene/boron nitride (GBN) monolayer heterosheets containing various types of interfacial structures has been studied using molecular dynamic simulations. The TR effect is ascribed to the asymmetric heat flow caused by mismatched PDOS of graphene and BN in the boundary. Additionally, the dependences of TR effects on boundary structures and defects are discussed. At a temperature difference of 240 K and interfacial chirality angle of 30°, a TR ratio as high as 334% is obtained. Our studies prove that the TR effect of GBN could be effectively regulated by controlling the interfacial structures and defects, and our analyses provide guidance on the structural designs of unique thermal management materials.Molecular force field simulation is an effective method to explore the properties of DNA molecules in depth. Almost all current popular force fields calculate atom-atom electrostatic interaction energies for DNAs based on the atomic charge and dipole or quadrupole moments, without considering high-rank atomic multipole moments for more accurate electrostatics. Actually, the distribution of electrons around atomic nuclei is not spherically symmetric but is geometry dependent. In this work, a multipole expansion method that allows us to combine polarizability and anisotropy was applied. One single-stranded DNA and one double-stranded DNA were selected as pilot systems. Deoxynucleotides were cut out from pilot systems and capped by mimicking the original DNA environment. Atomic multipole moments were integrated instead of fixed-point charges to calculate atom-atom electrostatic energies to improve the accuracy of force fields for DNA simulations. Also, the applicability of modeling the behavior of both single-stranded and double-stranded DNAs was investigated.