Partially collapsed cristobalite structure in the non molecular phase V in CO2
Non molecular CO2 has been an important subject of study in high pressure physics and chemistry for the past decade opening up a unique area of carbon chemistry. The phase diagram of CO2 includes several non molecular phases above 30 GPa. Among these, the first discovered was CO2-V which appeared si...
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| Published in | Proceedings of the National Academy of Sciences - PNAS Vol. 109; no. 14; pp. 5176 - 5179 |
|---|---|
| Main Authors | , , , , , , , |
| Format | Journal Article |
| Language | English |
| Published |
United States
National Academy of Sciences
03.04.2012
National Acad Sciences |
| Subjects | |
| Online Access | Get full text |
| ISSN | 0027-8424 1091-6490 1091-6490 |
| DOI | 10.1073/pnas.1118791109 |
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| Abstract | Non molecular CO2 has been an important subject of study in high pressure physics and chemistry for the past decade opening up a unique area of carbon chemistry. The phase diagram of CO2 includes several non molecular phases above 30 GPa. Among these, the first discovered was CO2-V which appeared silica-like. Theoretical studies suggested that the structure of CO2-V is related to that of β-cristobalite with tetrahedral carbon coordination similar to silicon in SiO2, but reported experimental structural studies have been controversial. We have investigated CO2-V obtained from molecular CO2 at 40–50 GPa and T > 1500 K using synchrotron X-ray diffraction, optical spectroscopy, and computer simulations. The structure refined by the Rietveld method is a partially collapsed variant of SiO2 β-cristobalite, space group Formula , in which the CO4 tetrahedra are tilted by 38.4° about the c-axis. The existence of CO4 tetrahedra (average O-C-O angle of 109.5°) is thus confirmed. The results add to the knowledge of carbon chemistry with mineral phases similar to SiO2 and potential implications for Earth and planetary interiors. |
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| AbstractList | Non molecular CO(2) has been an important subject of study in high pressure physics and chemistry for the past decade opening up a unique area of carbon chemistry. The phase diagram of CO(2) includes several non molecular phases above 30 GPa. Among these, the first discovered was CO(2)-V which appeared silica-like. Theoretical studies suggested that the structure of CO(2)-V is related to that of β-cristobalite with tetrahedral carbon coordination similar to silicon in SiO(2), but reported experimental structural studies have been controversial. We have investigated CO(2)-V obtained from molecular CO(2) at 40-50 GPa and T > 1500 K using synchrotron X-ray diffraction, optical spectroscopy, and computer simulations. The structure refined by the Rietveld method is a partially collapsed variant of SiO(2) β-cristobalite, space group I42d, in which the CO(4) tetrahedra are tilted by 38.4° about the c-axis. The existence of CO(4) tetrahedra (average O-C-O angle of 109.5°) is thus confirmed. The results add to the knowledge of carbon chemistry with mineral phases similar to SiO(2) and potential implications for Earth and planetary interiors. Non molecular CO(2) has been an important subject of study in high pressure physics and chemistry for the past decade opening up a unique area of carbon chemistry. The phase diagram of CO(2) includes several non molecular phases above 30 GPa. Among these, the first discovered was CO(2)-V which appeared silica-like. Theoretical studies suggested that the structure of CO(2)-V is related to that of β-cristobalite with tetrahedral carbon coordination similar to silicon in SiO(2), but reported experimental structural studies have been controversial. We have investigated CO(2)-V obtained from molecular CO(2) at 40-50 GPa and T > 1500 K using synchrotron X-ray diffraction, optical spectroscopy, and computer simulations. The structure refined by the Rietveld method is a partially collapsed variant of SiO(2) β-cristobalite, space group I42d, in which the CO(4) tetrahedra are tilted by 38.4° about the c-axis. The existence of CO(4) tetrahedra (average O-C-O angle of 109.5°) is thus confirmed. The results add to the knowledge of carbon chemistry with mineral phases similar to SiO(2) and potential implications for Earth and planetary interiors.Non molecular CO(2) has been an important subject of study in high pressure physics and chemistry for the past decade opening up a unique area of carbon chemistry. The phase diagram of CO(2) includes several non molecular phases above 30 GPa. Among these, the first discovered was CO(2)-V which appeared silica-like. Theoretical studies suggested that the structure of CO(2)-V is related to that of β-cristobalite with tetrahedral carbon coordination similar to silicon in SiO(2), but reported experimental structural studies have been controversial. We have investigated CO(2)-V obtained from molecular CO(2) at 40-50 GPa and T > 1500 K using synchrotron X-ray diffraction, optical spectroscopy, and computer simulations. The structure refined by the Rietveld method is a partially collapsed variant of SiO(2) β-cristobalite, space group I42d, in which the CO(4) tetrahedra are tilted by 38.4° about the c-axis. The existence of CO(4) tetrahedra (average O-C-O angle of 109.5°) is thus confirmed. The results add to the knowledge of carbon chemistry with mineral phases similar to SiO(2) and potential implications for Earth and planetary interiors. Non molecular CO 2 has been an important subject of study in high pressure physics and chemistry for the past decade opening up a unique area of carbon chemistry. The phase diagram of CO 2 includes several non molecular phases above 30 GPa. Among these, the first discovered was CO 2 -V which appeared silica-like. Theoretical studies suggested that the structure of CO 2 -V is related to that of β-cristobalite with tetrahedral carbon coordination similar to silicon in SiO 2 , but reported experimental structural studies have been controversial. We have investigated CO 2 -V obtained from molecular CO 2 at 40–50 GPa and T > 1500 K using synchrotron X-ray diffraction, optical spectroscopy, and computer simulations. The structure refined by the Rietveld method is a partially collapsed variant of SiO 2 β-cristobalite, space group , in which the CO 4 tetrahedra are tilted by 38.4° about the c -axis. The existence of CO 4 tetrahedra (average O-C-O angle of 109.5°) is thus confirmed. The results add to the knowledge of carbon chemistry with mineral phases similar to SiO 2 and potential implications for Earth and planetary interiors. Non molecular CO 2 has been an important subject of study in high pressure physics and chemistry for the past decade opening up a unique area of carbon chemistry. The phase diagram of CO 2 includes several non molecular phases above 30 GPa. Among these, the first discovered was CO 2 -V which appeared silica-like. Theoretical studies suggested that the structure of CO 2 -V is related to that of β-cristobalite with tetrahedral carbon coordination similar to silicon in SiO 2 , but reported experimental structural studies have been controversial. We have investigated CO 2 -V obtained from molecular CO 2 at 40–50 GPa and T > 1500 K using synchrotron X-ray diffraction, optical spectroscopy, and computer simulations. The structure refined by the Rietveld method is a partially collapsed variant of SiO 2 β-cristobalite, space group , in which the CO 4 tetrahedra are tilted by 38.4° about the c -axis. The existence of CO 4 tetrahedra (average O-C-O angle of 109.5°) is thus confirmed. The results add to the knowledge of carbon chemistry with mineral phases similar to SiO 2 and potential implications for Earth and planetary interiors. Non molecular CO2 has been an important subject of study in high pressure physics and chemistry for the past decade opening up a unique area of carbon chemistry. The phase diagram of CO2 includes several non molecular phases above 30 GPa. Among these, the first discovered was CO2-V which appeared silica-like. Theoretical studies suggested that the structure of CO2-V is related to that of β-cristobalite with tetrahedral carbon coordination similar to silicon in SiO2, but reported experimental structural studies have been controversial. We have investigated CO2-V obtained from molecular CO2 at 40–50 GPa and T > 1500 K using synchrotron X-ray diffraction, optical spectroscopy, and computer simulations. The structure refined by the Rietveld method is a partially collapsed variant of SiO2 β-cristobalite, space group Formula , in which the CO4 tetrahedra are tilted by 38.4° about the c-axis. The existence of CO4 tetrahedra (average O-C-O angle of 109.5°) is thus confirmed. The results add to the knowledge of carbon chemistry with mineral phases similar to SiO2 and potential implications for Earth and planetary interiors. Non molecular CO2 has been an important subject of study in high pressure physics and chemistry for the past decade opening up a unique area of carbon chemistry. The phase diagram of CO2 includes several non molecular phases above 30 GPa. Among these, the first discovered was CO2-V which appeared silica-like. Theoretical studies suggested that the structure of CO2-V is related to that of β-cristobalite with tetrahedral carbon coordination similar to silicon in SiO2, but reported experimental structural studies have been controversial. We have investigated CO2-V obtained from molecular CO2 at 40-50 GPa and T > 1500 K using synchrotron X-ray diffraction, optical spectroscopy, and computer simulations. The structure refined by the Rietveld method is a partially collapsed variant of SiO2 β-cristobalite, space group I42d , in which the CO4 tetrahedra are tilted by 38.4° about the c-axis. The existence of CO4 tetrahedra (average O-C-O angle of 109.5°) is thus confirmed. The results add to the knowledge of carbon chemistry with mineral phases similar to SiO2 and potential implications for Earth and planetary interiors. Non molecular CO2 has been an important subject of study in high pressure physics and chemistry for the past decade opening up a unique area of carbon chemistry. The phase diagram of CO2 includes several non molecular phases above 30 GPa. Among these, the first discovered was CO2-V which appeared silica-like. Theoretical studies suggested that the structure of CO2-V is related to that of β-cristobalite with tetrahedral carbon coordination similar to silicon in SiO2, but reported experimental structural studies have been controversial. We have investigated CO2-V obtained from molecular CO2 at 40–50 GPa and T > 1500 K using synchrotron X-ray diffraction, optical spectroscopy, and computer simulations. The structure refined by the Rietveld method is a partially collapsed variant of SiO2 β-cristobalite, space group Formula , in which the CO4 tetrahedra are tilted by 38.4° about the c-axis. The existence of CO4 tetrahedra (average O-C-O angle of 109.5°) is thus confirmed. The results add to the knowledge of carbon chemistry with mineral phases similar to SiO2 and potential implications for Earth and planetary interiors. |
| Author | Haines, Julien Gorelli, Federico A Levelut, Claire Santoro, Mario Scandolo, Sandro Bini, Roberto Montoya, Javier A Cambon, Olivier |
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| Notes | http://dx.doi.org/10.1073/pnas.1118791109 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 PMCID: PMC3325671 Author contributions: M.S., F.A.G., and J.H. designed research; M.S., F.A.G., R.B., J.H., O.C., C.L., J.A.M., and S.S. performed research; M.S., R.B., J.H., J.A.M., and S.S. analyzed data; and M.S. and J.H. wrote the paper. Edited by Russell J. Hemley, Carnegie Institution of Washington, Washington, DC, and approved January 24, 2012 (received for review November 16, 2011) |
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| Snippet | Non molecular CO2 has been an important subject of study in high pressure physics and chemistry for the past decade opening up a unique area of carbon... Non molecular CO 2 has been an important subject of study in high pressure physics and chemistry for the past decade opening up a unique area of carbon... Non molecular CO(2) has been an important subject of study in high pressure physics and chemistry for the past decade opening up a unique area of carbon... Non molecular CO 2 has been an important subject of study in high pressure physics and chemistry for the past decade opening up a unique area of carbon... |
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| SubjectTerms | carbon carbon dioxide Chemical Sciences chemistry computer simulation Material chemistry Physical Sciences physics silicon X-ray diffraction |
| Title | Partially collapsed cristobalite structure in the non molecular phase V in CO2 |
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