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recherche:projets:wurm [2017/01/19 11:29] cicaluga |
recherche:projets:wurm [2017/01/19 11:34] cicaluga [Presentation] |
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| The Raman spectra is plotted interactively, the user being able to visualize both single-crystal spectra and powder spectra and also to personalize the plots by rescaling, coloring etc. The information regarding the spectra is freely available for download. The database contains static tables for presenting the crystal structure information, for listing the frequency and the symmetry identification of the different modes in the zone-center and for reporting the Raman tensors. Interactive jmol-based animations illustrate the atomic displacement patterns of the different modes. Single-Raman spectra are available as a function of crystal orientation, for a basis of building a Raman microscope: | The Raman spectra is plotted interactively, the user being able to visualize both single-crystal spectra and powder spectra and also to personalize the plots by rescaling, coloring etc. The information regarding the spectra is freely available for download. The database contains static tables for presenting the crystal structure information, for listing the frequency and the symmetry identification of the different modes in the zone-center and for reporting the Raman tensors. Interactive jmol-based animations illustrate the atomic displacement patterns of the different modes. Single-Raman spectra are available as a function of crystal orientation, for a basis of building a Raman microscope: | ||
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| - | {{:recherche:projets:wurm2.jpg?nolink&600 |}} | + | * {{:recherche:projets:wurm2.jpg?nolink&600 |}} |
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| - | The WURM project supports NASA Mars2020 exploration mission, by offering the theoretical background for the Raman spectra. Mars2020 will carry two Raman spectrometers on the surface of Mars (Supercam instrument, co-developed in the Laboratory of Geology of Lyon, will be mounted on the rover of the NASA). We also compute energies of formation and hydration to help interpret the water and volatile cycles on Mars, to determine the effect of hydration on the Raman spectra, and to predict the isotope partitioning. | + | |
| + | The WURM project supports NASA Mars2020 exploration mission, by offering the theoretical background for the Raman spectra. Mars2020 will carry two Raman spectrometers on the surface of Mars (Supercam instrument, co-developed in the Laboratory of Geology of Lyon, will be mounted on the rover of the NASA). We also compute energies of formation and hydration to help interpret the water and volatile cycles on Mars, to determine the effect of hydration on the Raman spectra, and to predict the isotope partitioning. | ||
| We perform the first-principles calculations using the [[http://www.abinit.org/|ABINIT package]]. ABINIT is a package whose main program allows finding the total energy, charge density and electronic structure of systems made of electrons and nuclei (molecules and periodic solids) within Density Functional Theory (DFT), using pseudopotentials and a planewave basis. ABINIT also includes options to optimize the geometry according to the DFT forces and stresses, namely to find the stable theoretical crystal structure, to generate dynamical (vibrations - phonons) properties, like the Raman and infrared spectra, to compute the dielectric, mechanical or thermodynamical properties, etc. ABINIT is available through a [[http://www.gnu.org/copyleft/gpl.html|GNU General Public Licence (GPL)]]: the code-source is freely accessible and all contributions in the public domain are made available to the whole community of developers and users. | We perform the first-principles calculations using the [[http://www.abinit.org/|ABINIT package]]. ABINIT is a package whose main program allows finding the total energy, charge density and electronic structure of systems made of electrons and nuclei (molecules and periodic solids) within Density Functional Theory (DFT), using pseudopotentials and a planewave basis. ABINIT also includes options to optimize the geometry according to the DFT forces and stresses, namely to find the stable theoretical crystal structure, to generate dynamical (vibrations - phonons) properties, like the Raman and infrared spectra, to compute the dielectric, mechanical or thermodynamical properties, etc. ABINIT is available through a [[http://www.gnu.org/copyleft/gpl.html|GNU General Public Licence (GPL)]]: the code-source is freely accessible and all contributions in the public domain are made available to the whole community of developers and users. | ||