Efficacious calculation of Raman spectra in high pressure hydrogen

G. J. Ackland, I. B. Magdau

Research output: Contribution to journalArticlepeer-review

Abstract

We present and evaluate an efficient method for simulating Raman spectra from molecular dynamics calculations without defining normal modes. We apply the method to high pressure hydrogen in the high-temperature Phase IV: a plastic crystal in which the conventional picture of fixed phonon eigenmodes breaks down. Projecting trajectories onto in-phase molecular stretches is shown to be many orders of magnitude faster than polarisability calculations, allowing statistical averaging at high-temperature. The simulations are extended into metastable regimes and identify several regimes associated with symmetry-breaking on different timescales, which are shown to exhibit features in the Raman spectra at the current experimental limit of resolvability. In this paper we have concentrated on the methodology, a fuller description of the structure of Phase IV hydrogen is given in a previous paper [Magdau IB, Ackland GJ. Identification of high-pressure phases III and IV in hydrogen: simulating Raman spectra using molecular dynamics. Phys Rev B. 2013;87:174110].

Original languageEnglish
Pages (from-to)198-204
Number of pages7
JournalHigh Pressure Research
Volume34
Issue number2
DOIs
Publication statusPublished - Jun 2014

Keywords

  • hydrogen
  • lattice dynamics
  • Raman

Fingerprint Dive into the research topics of 'Efficacious calculation of Raman spectra in high pressure hydrogen'. Together they form a unique fingerprint.

Cite this