Bulk and surface energetics of crystalline lithium hydride: Benchmarks from quantum Monte Carlo and quantum chemistry

Binnie, S. J. and Nolan, S. J. and Drummond, Neil and Alfe, D and Allan, N. L. and Manby, F. R. and Gillan, M. J. (2010) Bulk and surface energetics of crystalline lithium hydride: Benchmarks from quantum Monte Carlo and quantum chemistry. Physical review B, 82 (16). ISSN 1550-235X

[img]
Preview
PDF
e165431.pdf - Published Version

Download (186kB)

Abstract

We show how accurate benchmark values of the surface formation energy of crystalline lithium hydride can be computed by the complementary techniques of quantum Monte Carlo (QMC) and wave-function-based molecular quantum chemistry. To demonstrate the high accuracy of the QMC techniques, we present a detailed study of the energetics of the bulk LiH crystal, using both pseudopotential and all-electron approaches. We show that the equilibrium lattice parameter agrees with experiment to within 0.03%, which is around the experimental uncertainty, and the cohesive energy agrees to within around 10 meV/f.u. QMC in periodic slab geometry is used to compute the formation energy of the LiH (001) surface, and we show that the value can be accurately converged with respect to slab thickness and other technical parameters. The quantum chemistry calculations build on the recently developed hierarchical scheme for computing the correlation energy of a crystal to high precision. We show that the hierarchical scheme allows the accurate calculation of the surface formation energy, and we present results that are well converged with respect to basis set and with respect to the level of correlation treatment. The QMC and hierarchical results for the surface formation energy agree to within about 1%.

Item Type:
Journal Article
Journal or Publication Title:
Physical review B
Additional Information:
© 2010 The American Physical Society
Uncontrolled Keywords:
/dk/atira/pure/researchoutput/libraryofcongress/qc
Subjects:
ID Code:
55594
Deposited By:
Deposited On:
10 Jul 2012 07:56
Refereed?:
Yes
Published?:
Published
Last Modified:
23 Oct 2020 01:49