Four-body interaction energy for compressed solid krypton from quantum theory

2012 ◽  
Vol 137 (4) ◽  
pp. 044108 ◽  
Author(s):  
Chunling Tian ◽  
Na Wu ◽  
Fusheng Liu ◽  
Surendra K. Saxena ◽  
Xingrong Zheng

The electronic contribution to the dynamical tensors is examined in more detail and the following results are obtained. First the electronic contribution is shown to be translationally invariant, secondly the assumption that this term can be approximately represented by a two-body interaction is shown to be equivalent to a rigid ion model, and finally this approximation is shown to become exact in the limit q = 0.


2019 ◽  
Vol 807 ◽  
pp. 135-140
Author(s):  
Xi Jin Fu

Based on the first-principles, using CCSD(T) ab initio calculation method, many-body potential energy of solid argon are accurately calculated with the atomic distance R from 2.0Å to 3.6Å at T=300K, and firstly establish and discuss the face-centered cubic (fcc) atomic crystal configurations of two-, three-, and four-body terms by geometry optimization. The results shows that the total number of (Ar)2 clusters is 903, which belongs to 12 different geometric configurations, the total number of (Ar)3 clusters is 861, which belongs to 25 different geometric configurations, and the total number of (Ar)4 clusters of is 816 which belongs to 27 different geometric configurations. We find that the CCSD(T) with the aug-cc-pVQZ basis set is most accurate and practical by comprehensive consideration. The total potential energy Un reachs saturation at R>2.0Å when the only two-and three-body interaction energy are considered. When R≤2.0Å, the total potential energy Un must consider four-and higher-body interaction energy to achieve saturation. Many-body expansion potential of fcc solid argon is an exchange convergent series.


2004 ◽  
Vol 03 (01) ◽  
pp. 15-22 ◽  
Author(s):  
JINSHAN LI ◽  
FUQIAN JING

Nonadditive three- and four-body interaction energies have been calculated for HF tetramer at the MP2/aug-cc-pVTZ level and for H 2 tetramer at the MP4(SDTQ)/aug-cc-pVTZ level using the so-called fifteen-point method. Calculated results show that with intermolecular distances decreasing from 3.0 to 1.7 Å the nonadditive three- and four-body interactions may be: (a) more and more attractive; (b) more and more repulsive; or (c) extremely weak. Strangely the minimum point of nonadditive three- and four-body interaction potentials has not been found up to now. For both H 2 and HF tetramers the nonadditive four-body interaction energy makes a negligible contribution to total binding energy when intermolecular distances are compressed from 3.0 to 1.7 Å.


2021 ◽  
Vol 23 (1) ◽  
pp. 233
Author(s):  
Małgorzata Domagała ◽  
Sílvia Simon and Marcin Palusiak

In the presented research, we address the original concept of resonance-assisted hydrogen bonding (RAHB) by means of the many-body interaction approach and electron density delocalization analysis. The investigated molecular patterns of RAHBs are open chains consisting of two to six molecules in which the intermolecular hydrogen bond stabilizes the complex. Non-RAHB counterparts are considered to be reference systems. The results show the influence of the neighbour monomers on the unsaturated chains in terms of the many-body interaction energy contribution. Exploring the relation between the energy parameters and the growing number of molecules in the chain, we give an explicit extrapolation of the interaction energy and its components in the infinite chain. Electron delocalization within chain motifs has been analysed from three different points of view: three-body delocalization between C=C-C, two-body hydrogen bond delocalization indices and also between fragments (monomers). A many-body contribution to the interaction energy as well as electron density helps to establish the assistance of resonance in the strength of hydrogen bonds upon the formation of the present molecular chains. The direct relation between interaction energy and delocalization supports the original concept, and refutes some of the criticisms of the RAHB idea.


Author(s):  
Giuliano Lazzaroni ◽  
Ulisse Stefanelli

Abstract We investigate the minimization of configurational energies of Brenner type. These include two- and three-body interaction terms, which favor the alignment of first neighbors. In particular, such configurational energies arise in connection with the molecular-mechanical modeling of covalent$sp$-bonding in carbon. Ground states in three dimensions are characterized and the stability of chains and rings is discussed. The interaction energy is then augmented with terms corresponding to weaker interactions favoring the stratification of configurations. This gives rise to stratified structures, which are reminiscent of nanoscrolls and multi-wall nanotubes. Optimal stratified configurations are identified and their geometry is discussed.


1992 ◽  
Vol 07 (supp01b) ◽  
pp. 805-812 ◽  
Author(s):  
PIOTR PODLEŚ

The particles interchanging operator and hamiltonian for two particles on a quantum sphere are constructed. Though there is no interaction hamiltonian, "interaction energy" occurs. It suggests a possibility that in a future quantum theory, all particles might be free.


The dynamics of a crystal is examined on the basis of the adiabatic approximation. In part I we examine the form of the dynamical and anharmonic tensors on the assumption that the effective nuclear potential energy can be represented as a simple two-body interaction. In part II we derive expressions for the electronic contributions on the basis of the Hartree-Fock approximation and show that these electron-nuclear interactions are more complex than a simple two-body interaction. In part III we examine these interactions in more detail and find that the two-body approximation is equivalent to a rigid-ion model and that this approximation becomes exact in the limit q = 0.


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