Calcium orthocarbonate, Ca2CO4-Pnma: A potential host for subducting carbon in the transition zone and lower mantle

Dinara Sagatova, Anton Shatskiy, Nursultan Sagatov, Pavel N. Gavryushkin, Konstantin D. Litasov

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

A novel structure of calcium orthocarbonate Ca2CO4-Pnma has been discovered using ab-initio crystal structure prediction methods (AIRSS and USPEX) based on the density functional theory. This phase appears above 13 GPa and remains stable to at least 50 GPa and 2000 K according to the calculations within quasi-harmonic approximation. Thus, the discovered phase can be stable at Earth's transition zone and lower mantle P-T conditions. The carbon atoms in the discovered phase are presented in 4-fold coordination, and its structure is similar to the high-pressure and high-temperature α'H-Ca2SiO4 phase.

Original languageEnglish
Article number105637
Number of pages5
JournalLithos
Volume370-371
DOIs
Publication statusPublished - 1 Oct 2020

Keywords

  • CaCO
  • Density functional theory
  • Lower mantle
  • Orthocarbonate
  • Subduction
  • Transitions zone
  • HIGH-PRESSURE
  • INCLUSIONS
  • DIAMOND
  • Otthocarbonate
  • AB-INITIO
  • CACO3
  • POLYMORPHS
  • BRAZIL
  • PHASE
  • Ca2CO4
  • MINERALOGY
  • ARAGONITE

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