inelastic subproject report b. fultz, caltech
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Inelastic Subproject Report B. Fultz, Caltech. Scope of Science in WBS 10 Tasks and goals of the DANSE subproject Release Plans Risks and Challenges. WBS 10: Science Scope for Inelastic Scattering. - PowerPoint PPT PresentationTRANSCRIPT
Inelastic Subproject Report B. Fultz, Caltech
Scope of Science in WBS 10Tasks and goals of the DANSE subprojectRelease Plans
Risks and Challenges
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
PublicationTrends
Density Functionaland Scattering
1.4x10-3
1.2
1.0
0.8
0.6
0.4
0.2
0.020062004200220001998199619941992
Year
Papers_LDAGGA_n(inelastic OR diffract*) AND (neutron OR X-ray) AND (GGA OR (LDA NOT ICE))
Papers_GGA_n(inelastic OR diffract*) AND (neutron OR X-ray) AND GGA 2006 incomplete
Roadmap of Sept. 2001
ExperimentalData
Simulation
AcyclicTransformations
Modeling
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)
Idea: Multiple Incident Energies for Higher Resolution
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
Simulation Framework (package diagram with dependencies)
Ab-Initio: Release 2007 Olivier Delaire
crystal structure
displacement generator
supercell generator
distorted supercell generator
DFT engineforce calculator
IFC calculatorBvK package
uses
uses
Takes IFC
object
based on
DFT engine
Crystal structurek-point gridaccuracy params
GS energyGS densityforces on nuclei
VASP Wien2kAbinit
crystal structure
atomsbasis vectorslattice vectors
isEquivalent()
1
Ab-Initio: Two features for 2007
Ab Initio Simulation uses
Prototype results
Experiment (Pharos) Bv-K Model (Brockhouse) VASP (mag Ni)
Chemical Physics: Brandon Keith Starts Feb. 2007
• Molecular Dynamics -- GULP• Gaussian Basis Set LDA (GAMESS, NWCHEM)• Normal Mode Analysis (CLIMAX, nMOLDYN)
API DesignData Object DesignPrioritization and release plans TBA
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
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
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
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.
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.
Summary of WBS 10: Inelastic Scattering
1) Scope for:- dynamics of small molecules- elementary excitations in solids
2) Reduction application is mature. Plans for Release 1.2.
3) Prototypes exist for many of the main deliverables, and parts of many others have been tried.
4) Staff in place for all scope.
5) Nearly all functionality can be available in some form in 2008.