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Inelastic Subproject Report B. Fultz, Caltech

Inelastic Subproject Report B. Fultz, Caltech

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Inelastic Subproject Report B. Fultz, Caltech

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  1. Inelastic Subproject ReportB. Fultz, Caltech Scope of Science in WBS 10Tasks and goals of the DANSE subprojectRelease PlansRisks and Challenges

  2. WBS 10: Science Scope for Inelastic Scattering 1) spin correlations in magnets, superconductors, and materials close to metal-insulator transitions 2) vibrational excitations in solids and their relationship to phase diagrams and equations of state of materials 3) tunneling and reorientation transitions of small molecules on surfaces 4) vibrational spectra of molecules or individual atoms such as hydrogen 5) diffusional motions and relaxation processes studied by quasielastic scattering

  3. PublicationTrendsDensity Functionaland Scattering

  4. Experimental Data Acyclic Transformations Simulation Modeling Roadmap of Sept. 2001

  5. Inelastic Reduction Software Release 1.1 • Occurred on schedule • 3,789 files, more in svn repository • 2 dozen packages, emphasis on Reduction (also simulation) • Binaries for Windows XP, Mac OS 10, Linux • Modular components - reduction framework Release 1.2 plans: • ARCS itself (need data to try it out) • Multiphonon correction (several versions available) • Multiple scattering correction (see Max Kresch’s poster) • Detector visualization (Jiao has a demo) • September 2007 release (tentative)

  6. Idea: Multiple Incident Energies for Higher Resolution

  7. Simulation Framework: Jiao Lin 2007 •  Release in 2007 • Extensions to phonon scattering with dynamics model • Scattering from correlation functions G(r,t) (q,E) • Documentation

  8. Simulation Framework (package diagram with dependencies)

  9. crystal structure displacement generator supercell generator distorted supercell generator DFT engine force calculator IFC calculator BvK package Ab-Initio:  Release 2007 Olivier Delaire based on uses uses Takes IFC object

  10. Ab-Initio: Two features for 2007 DFT engine crystal structure 1 Crystal structure k-point grid accuracy params atoms basis vectors lattice vectors Ab Initio Simulation GS energy GS density forces on nuclei isEquivalent() VASP Abinit Wien2k uses

  11. Experiment (Pharos) Bv-K Model (Brockhouse) VASP (mag Ni) Prototype results

  12. Chemical Physics: Brandon Keith Starts Feb. 2007 • Molecular Dynamics -- GULP • Gaussian Basis Set LDA (GAMESS, NWCHEM) • Normal Mode Analysis (CLIMAX, nMOLDYN) API Design Data Object Design Prioritization and release plans TBA

  13. Plans for 2008 • Chemical Physics • Magnetic scattering (magnon models) • Single crystals using UB matrix • Fits to noisy dispersive information • Separation of phonons and magnons by Q-dependence • Neutron weight correction (prototypes in use now) • SEQUOIA and CNCS (TBA) • Black absorber

  14. Education and Outreach • Textbooks • Students - J. Munoz, U. Texas El Paso, underrepresented minority student - Eliot Setzer, Caltech CS undergraduate - M. Kresch, Chen Li, Caltech graduate students

  15. Inelastic Effort Today • Fully staffed - Jiao Lin - Olivier Delaire - Brandon Keith - Max Kresch (grad student) • Working to find science niches for everyone, consistent with project tasks • Close feedback to DANSE management on practices

  16. Risks (and Opportunities) • Direction in magnetic scattering -- requires real science, funds, beamtime. • Direction in chemical physics -- requires real science, funds, beamtime. • Robustness of fitting dispersive information in noisy data -- ideas may change as source power increases at SNS. • Some legacy code is not documented well, but may need new functionality. • Microsoft Windows and user expectations. • User science expertise needs to be high for some applications. • How do we support users? • Life may get dull for developers.

  17. Reasons for Confidence and Optimism • Most of the large science packages have been tested. • Prototypes have been tested for many of the 5-year deliverables. • Software development process becoming more agile. • Staff skills are international-class.

  18. Summary of WBS 10: Inelastic Scattering Scope for: - dynamics of small molecules - elementary excitations in solids Reduction application is mature. Plans for Release 1.2. Prototypes exist for many of the main deliverables, and parts of many others have been tried. Staff in place for all scope. Nearly all functionality can be available in some form in 2008.