by: shaun pacheco harvey mudd college advisor: dr. patrick...
TRANSCRIPT
![Page 1: By: Shaun Pacheco Harvey Mudd College Advisor: Dr. Patrick ...ww2.che.ufl.edu/reu/student_presentations/2011/... · References Payne, et al. “Iterative minimization techniques for](https://reader034.vdocuments.us/reader034/viewer/2022042319/5f08cfd47e708231d423d694/html5/thumbnails/1.jpg)
By:ShaunPachecoHarveyMuddCollege
Advisor:Dr.PatrickSchellingUniversityofCentralFlorida
![Page 2: By: Shaun Pacheco Harvey Mudd College Advisor: Dr. Patrick ...ww2.che.ufl.edu/reu/student_presentations/2011/... · References Payne, et al. “Iterative minimization techniques for](https://reader034.vdocuments.us/reader034/viewer/2022042319/5f08cfd47e708231d423d694/html5/thumbnails/2.jpg)
SilicateMinerals Compoundbearingsiliconanion Foundinuppermantle(90%ofcrust)
Olivine(Mg,Fe)2SiO4 Asteroids Weathersquickly
http://en.wikipedia.org/wiki/File:Peridot2.jpg
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SiliconTetrahedron 3differentoxygensites
O1furthestoxygen O2closestoxygen O3equidistant
O2
O3
O3
O1 Si
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StructureofOlivineM2SiO4
Orthorombic ForsteriteMg2SiO4
FayaliteFe2SiO4 Twometalsites FeprefersM1siteM1
M1
M2
M2
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Op8calProper8es DependentonMagnesium‐Ironconcentration
Iron’svalenceelectronsleadstosmallerbandgap
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Fayalite
http://en.wikipedia.org/wiki/File:Fayalite_crystal_group_‐_Ochtendung,_Eifel,_Germany.jpg
http://en.wikipedia.org/wiki/File:Forsterite_on_Sanidine_‐_Ochtendung,_Eifel,_Germany.jpg
Forsterite
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DensityFunc8onalTheory Ground‐stateenergyuniquefunctionaloftheelectrondensity
Findsetofwavefunctionsthatminimizeenergyfunctional.
!
"!2
2me
+Veff (" r )
#
$ %
&
' ( )* (" r ) = E*)* (
" r )
!
n! r ( ) = "#
$ ! r ( )"#
! r ( )
#
occ
%
![Page 8: By: Shaun Pacheco Harvey Mudd College Advisor: Dr. Patrick ...ww2.che.ufl.edu/reu/student_presentations/2011/... · References Payne, et al. “Iterative minimization techniques for](https://reader034.vdocuments.us/reader034/viewer/2022042319/5f08cfd47e708231d423d694/html5/thumbnails/8.jpg)
PointDefects SchottkyDefect–defectconsistingofananionandcationvacancyinfinitelyfarapart
SchottkyDefectClusters–defectconsistingofananionandcationvacancy
http://en.wikipedia.org/wiki/File:Naclschottkydefect.svg
![Page 9: By: Shaun Pacheco Harvey Mudd College Advisor: Dr. Patrick ...ww2.che.ufl.edu/reu/student_presentations/2011/... · References Payne, et al. “Iterative minimization techniques for](https://reader034.vdocuments.us/reader034/viewer/2022042319/5f08cfd47e708231d423d694/html5/thumbnails/9.jpg)
SpaceWeathering Createspointdefects Micrometeoriteimpacts Solar‐windsputtering Interactionswithcosmicrays
![Page 10: By: Shaun Pacheco Harvey Mudd College Advisor: Dr. Patrick ...ww2.che.ufl.edu/reu/student_presentations/2011/... · References Payne, et al. “Iterative minimization techniques for](https://reader034.vdocuments.us/reader034/viewer/2022042319/5f08cfd47e708231d423d694/html5/thumbnails/10.jpg)
FiniteSizeEffects
SmallSystemMg1O3
LargerSystemMg1O3
M2
M2
M1
M2
M2 M1
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SchoFkyDefectResults Forsterite:
Mg2‐O3defectlowestenergy3.65eV Mg2‐O2defecthighestenergy7.52eV
Differentresultsthanempiricalpotentials
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OxygenVacancy Forsterite:O2sitemostenergeticallyfavorable8.45eV
Fayalite:O3sitemostenergeticallyfavorable7.90eV
M1
M1
M2
M2
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FutureWork Biggercellsizes Furtherstudyopticalproperties Propertiesofolivineasfunctionofironcontent Surfaces
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Ques8ons?
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References Payne,etal.“Iterativeminimizationtechniquesforabinitiototal‐energycalculations:
moleculardynamicsandconjugategradients.”Oct1992. http://en.wikipedia.org/wiki/File:Peridot2.jpg http://en.wikipedia.org/wiki/File:Forsterite_on_Sanidine_‐
_Ochtendung,_Eifel,_Germany.jpg http://en.wikipedia.org/wiki/File:Fayalite_crystal_group_‐
_Ochtendung,_Eifel,_Germany.jpg http://en.wikipedia.org/wiki/File:Naclschottkydefect.svg