2001/04/12 by T. Cui, Tianhong Cui, Y. Takada +7
Earth and Planetary Sciences · Physics and Astronomy · #Advanced Chemical Physics Studies #High-pressure geophysics and materials #Quantum, superfluid, helium dynamics #cond-mat.mtrl-sci #cond-mat.stat-mech
paper · pdf · doi:10.1103/physrevb.64.024108
8 pages, 7 figures; accepted in Phys. Rev. B
arxiv created 2001/04/12 · openalex publication_date 2001/06/22 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We study the effect of temperature up to 1000 K on the structure of dense molecular para-hydrogen (p\ensuremath-H2) and ortho-deuterium (o\ensuremath-D2), using the path-integral Monte Carlo method. We find a structural phase transition from orientationally disordered hexagonal close packed (hcp) to an orthorhombic structure of Cmca symmetry before melting. The transition is basically induced by thermal fluctuations, but quantum fluctuations of protons (deuterons) are important in determining the transition temperature through effectively hardening the intermolecular interaction. We estimate the phase line between hcp and Cmca phases as well as the melting line of the Cmca solid.