scholarly journals Semiclassical expansion of quantum characteristics for many-body potential scattering problem

2007 ◽  
Vol 16 (9) ◽  
pp. 587-614 ◽  
Author(s):  
M.I. Krivoruchenko ◽  
C. Fuchs ◽  
A. Faessler
Keyword(s):  
Scattering Problem ◽  
Potential Scattering ◽  
Many Body ◽  
Body Potential ◽  
Semiclassical Expansion

scholarly journals Low-energy Electron Scattering from Polyatomic Molecules: The Role of Electron Correlation

1992 ◽  
Vol 45 (3) ◽  
pp. 337 ◽  
Author(s):  
C William McCurdy
Keyword(s):  
Electron Scattering ◽  
Scattering Problem ◽  
Bound State ◽  
Potential Scattering ◽  
Theoretical Description ◽  
Polyatomic Molecules ◽  
Many Body ◽  
Low Energy Electron ◽  
Impact Energies

Until recently the principal barrier to the accurate theoretical description of electronic collisions with polyatomic molecules was the problem of scattering by a nonlocal potential which is arbitrarily asymmetric. The last five or six years have seen the development of numerical techniques capable of solving the potential scattering problem, and the first applications of methods for treating many-body aspects of collisions of electrons with polyatomic molecules are beginning to appear in the literature. We describe the complex Kohn method and the use, in scattering calculations, of methods for treating electronic correlation which are standard in bound-state quantum chemistry. As examples of the application of these ideas we present the results of calculations on electron scattering from CH4, SiH4 and C2H6. All of these molecules exhibit Ramsauer-Townsend minima at low impact energies which are entirely correlation effects.

Data-Driven Many-Body Models with Chemical Accuracy for CH4/H2O Mixtures

2020 ◽  
Author(s):  
Marc Riera ◽  
Alan Hirales ◽  
Raja Ghosh ◽  
Francesco Paesani
Keyword(s):  
Liquid Phase ◽  
Quantitative Description ◽  
Liquid Mixtures ◽  
Many Body ◽  
Energy Functions ◽  
Potential Energy Functions ◽  
Dynamics Simulations ◽  
Body Potential ◽  
Small Clusters ◽  
Many Body Interactions

<div> <div> <div> <p>Many-body potential energy functions (PEFs) based on the TTM-nrg and MB-nrg theoretical/computational frameworks are developed from coupled cluster reference data for neat methane and mixed methane/water systems. It is shown that that the MB-nrg PEFs achieve subchemical accuracy in the representation of individual many-body effects in small clusters and enables predictive simulations from the gas to the liquid phase. Analysis of structural properties calculated from molecular dynamics simulations of liquid methane and methane/water mixtures using both TTM-nrg and MB-nrg PEFs indicates that, while accounting for polarization effects is important for a correct description of many-body interactions in the liquid phase, an accurate representation of short-range interactions, as provided by the MB-nrg PEFs, is necessary for a quantitative description of the local solvation structure in liquid mixtures. </p> </div> </div> </div>

scholarly journals The phase diagram of carbon dioxide from correlation functions and a many-body potential

2021 ◽  
Vol 155 (2) ◽  
pp. 024503
Author(s):  
Amanda A. Chen ◽  
Alexandria Do ◽  
Tod A. Pascal
Keyword(s):  
Carbon Dioxide ◽  
Phase Diagram ◽  
Correlation Functions ◽  
Many Body ◽  
Body Potential

scholarly journals $$\hbox {Ag}_{m} \hbox {Rh}_n$$ clusters with $$m+n\le 55$$

2021 ◽  
Vol 140 (4) ◽  
Author(s):  
Nicolas Louis ◽  
Stephan Kohaut ◽  
Michael Springborg
Keyword(s):  
Genetic Algorithms ◽  
Structure Optimization ◽  
Structural Similarity ◽  
Similarity Function ◽  
Many Body ◽  
Coordination Numbers ◽  
Energetic Properties ◽  
Ag Clusters ◽  
Body Potential ◽  
Mixed Clusters

AbstractUsing a combination of genetic algorithms for the unbiased structure optimization and a Gupta many-body potential for the calculation of the energetic properties of a given structure, we determine the putative total-energy minima for all $$\hbox {Ag}_{m} \hbox {Rh}_n$$ Ag m Rh n clusters with a total number of atoms $$m+n$$ m + n up to 55. Subsequently, we use various descriptors to analyze the obtained structural and energetic properties. With the help of a similarity function, we show that the pure Ag and Rh clusters are structurally similar for sizes up to around 20 atoms. The same approach gives that the mixed clusters tend to possess a larger structural similarity with the pure Rh clusters than with the pure Ag clusters. However, for clusters with $$m\simeq n\ge 25$$ m ≃ n ≥ 25 , other structures dominate. The effective coordination numbers for the Ag and Rh atoms as well as the radial distributions of those atoms indicate that there is a tendency towards segregation with Rh atoms forming an inner part and the Ag atoms forming a shell. Only few clusters, all with a fairly large total number of atoms, are found to be particularly stable.

Empirical many-body potential energy functions for iron

1993 ◽  
Vol 97 (46) ◽  
pp. 12073-12082 ◽  
Author(s):  
Fei Gao ◽  
Roy L. Johnston ◽  
John N. Murrell
Keyword(s):  
Potential Energy ◽  
Many Body ◽  
Energy Functions ◽  
Potential Energy Functions ◽  
Body Potential

scholarly journals Study of Zero Temperature Ground State Properties of the Repulsive Bose-Einstein Condensate in an Anharmonic Trap

2021 ◽  
Vol 13 (3) ◽  
pp. 733-744
Author(s):  
P. K. DEBNATH
Keyword(s):  
Ground State ◽  
Expansion Method ◽  
Einstein Condensate ◽  
Zero Temperature ◽  
Many Body ◽  
Ground State Properties ◽  
Potential Harmonic ◽  
The Stability ◽  
Average Size ◽  
Body Potential

The zero-temperature ground state properties of experimental 87Rb condensate are studied in a harmonic plus quartic trap [ V(r) =  ½mω2r2 + λr4 ]. The anharmonic parameter (λ) is slowly tuned from harmonic to anharmonic. For each choice of λ, the many-particle Schrödinger equation is solved using the potential harmonic expansion method and determines the lowest effective many-body potential. We utilize the correlated two-body basis function, which keeps all possible two-body correlations. The use of van der Waals interaction gives realistic pictures. We calculate kinetic energy, trapping potential energy, interaction energy, and total ground state energy of the condensate in this confining potential, modelled experimentally. The motivation of the present study is to investigate the crucial dependency of the properties of an interacting quantum many-body system on λ. The average size of the condensate has also been calculated to observe how the stability of repulsive condensate depends on anharmonicity. In particular, our calculation presents a clear physical picture of the repulsive condensate in an anharmonic trap.

GLOBAL MINIMA FOR PdN (N = 5–80) CLUSTERS DESCRIBED BY SUTTON–CHEN POTENTIAL

2007 ◽  
Vol 18 (08) ◽  
pp. 1351-1359 ◽  
Author(s):  
HAYDAR ARSLAN
Keyword(s):  
Monte Carlo ◽  
Energy Surface ◽  
Central Atom ◽  
Low Energy ◽  
Global Minima ◽  
Many Body ◽  
Pd Clusters ◽  
Body Potential ◽  
Basin Hopping ◽  
Theoretical Results

The structure and energetics of Pd N (N = 5–80) clusters have been studied extensively by a Monte Carlo method based on Sutton–Chen many-body potential. The basin-hopping algorithm is used to find the low-energy minima on the potential energy surface for each nuclearity. A variety of structure types (icosahedral, decahedral and fcc closed-packed) are observed for Pd clusters. Some of the icosahedral global minima do not have a central atom. The resulting structures have been compared with the previous theoretical results.

ATOMISTIC SCALE SIMULATION OF TEXTURED SURFACES ON DRY SLIDING FRICTION

2013 ◽  
Vol 37 (3) ◽  
pp. 927-936 ◽  
Author(s):  
Ming-Yuan Chen ◽  
Zheng-Han Hong ◽  
Te-Hua Fang ◽  
Shao-Hui Kang ◽  
Li-Min Kuo
Keyword(s):  
Sliding Friction ◽  
Surface Texturing ◽  
Dynamics Simulation ◽  
Embedded Atom Method ◽  
Textured Surface ◽  
Textured Surfaces ◽  
Many Body ◽  
Embedded Atom ◽  
Modified Embedded Atom Method ◽  
Body Potential

Fe sliding on a Fe substrate with surface texturing is investigated using molecular dynamics simulation. The modified embedded-atom method many-body potential is used to describe the interaction of Fe atoms. The tribological properties of surface texturing during nanosliding are discussed. Results indicate that a textured surface has lower friction than that of a flat surface. In addition, a surface with parallel grooves has lower friction than that of a dimpled surface. Hence, surface texturing greatly affects friction.

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