6533b856fe1ef96bd12b2fec

RESEARCH PRODUCT

Lattice distortion of hcp solid helium under pressure

Ho-kwang MaoS. M. TretyakAlexei GrechnevAlexander F. GoncharovRussell J. HemleyDaniel ErrandoneaJohn S. TseYu. A. Freiman

subject

Classical mechanicsMaterials scienceCondensed matter physicschemistryLattice (order)Lattice distortionchemistry.chemical_elementElongationCondensed Matter PhysicsFlatteningHeliumElectronic Optical and Magnetic Materials

description

The lattice distortion of hcp solid He under pressure is calculated using semiempirical and first-principle approaches. While three-body forces tend to flatten the lattice at all compressions, the effect of pair forces changes from the flattening at small compression to elongation at large one. At large compressions, the lattice distortion due to the triple forces is more than twice as large as those due to pair forces and the lattice is slightly flattened. First-principles results show that over approximately fivefold compressions higher-order, many-body forces become important.

https://doi.org/10.1103/physrevb.80.094112