Quantum Monte Carlo, density functional theory, and pair potential studies of solid neon

Drummond, Neil and Needs, R. J. (2006) Quantum Monte Carlo, density functional theory, and pair potential studies of solid neon. Physical review B, 73 (2): 024107. ISSN 1550-235X

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Abstract

We report quantum Monte Carlo (QMC), plane-wave density-functional theory (DFT), and interatomic pair-potential calculations of the zero-temperature equation of state (EOS) of solid neon. We find that the DFT EOS depends strongly on the choice of exchange-correlation functional, whereas the QMC EOS is extremely close to both the experimental EOS and the EOS obtained using the best semiempirical pair potential in the literature. This suggests that QMC is able to give an accurate treatment of van der Waals forces in real materials, unlike DFT. We calculate the QMC EOS up to very high densities, beyond the range of values for which experimental data are currently available. At high densities the QMC EOS is more accurate than the pair-potential EOS. We generate a different pair potential for neon by a direct evaluation of the QMC energy as a function of the separation of an isolated pair of neon atoms. The resulting pair potential reproduces the EOS more accurately than the equivalent potential generated using the coupled-cluster CCSD(T) method.

Item Type:
Journal Article
Journal or Publication Title:
Physical review B
Additional Information:
© 2006 The American Physical Society
Uncontrolled Keywords:
/dk/atira/pure/core/keywords/physics
Subjects:
?? physicsqc physics ??
ID Code:
55608
Deposited By:
Deposited On:
10 Jul 2012 08:33
Refereed?:
Yes
Published?:
Published
Last Modified:
02 Mar 2024 01:13