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

Author
Abstract
:

The importance of the four-body contribution in compressed solid krypton was first evaluated using the many-body expansion method and the coupled cluster theory with full single and double excitations plus perturbative treatment of triples. All different four-atom clusters existing in the first- and second-nearest neighbor shells of face-centered cubic krypton were considered, and both self-consistent-field Hartree-Fock and correlation parts of the four-body interaction were accurately determined from the ambient conditions up to eightfold volume compression. We find that the four-body interaction energy is negative at compression ratio lower than 2, where the dispersive forces play a dominant role. With increasing the compression, the four-body contribution becomes repulsive and significantly cancels the over-softening effects of the three-body potential. The obtained equation of state (EOS) was compared with the experiments and the density-functional theory calculations. It shows that combination of the four-body effects with two- and three-body interactions leads to an excellent agreement with EOS measurements throughout the whole experimental range 0-130 GPa, and extends the prediction to 300 GPa.

Year of Publication
:
2012
Journal
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The Journal of chemical physics
Volume
:
137
Issue
:
4
Number of Pages
:
044108
Date Published
:
2012
ISSN Number
:
0021-9606
URL
:
https://dx.doi.org/10.1063/1.4737183
DOI
:
10.1063/1.4737183
Short Title
:
J Chem Phys
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