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000021585 037__ $$aPreJuSER-21585
000021585 1001_ $$0P:(DE-Juel1)144723$$aDi Napoli, E.$$b0$$uFZJ
000021585 1112_ $$cArgonne, USA$$d2012-04-05
000021585 245__ $$aEigenproblems and Eigensolvers in Density Functional Theory
000021585 260__ $$c2012
000021585 29510 $$aSeminar at Argonne Leadership Computing Facility
000021585 3367_ $$0PUB:(DE-HGF)31$$2PUB:(DE-HGF)$$aTalk (non conference)$$xInvited
000021585 3367_ $$033$$2EndNote$$aConference Paper
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000021585 3367_ $$2DINI$$aOther
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000021585 3367_ $$2ORCID$$aLECTURE_SPEECH
000021585 500__ $$aRecord converted from VDB: 12.11.2012
000021585 500__ $$3Talk (non conference)
000021585 520__ $$aIn DFT based simulations each SCF cycle comprises dozens of large generalized eigenproblems. In a recent study, it has been proposed to consider simulations as made of dozens of sequences of eigenvalue problems, where each sequence groups together eigenproblems with equal k-vector and increasing iteration index i. It was then demonstrated that successive eigenproblems in a sequence are strongly correlated to one another. In particular, by tracking the evolution over iterations of the angle between eigenvectors of adjacent iterations, it was shown the angles decrease noticeably after the first few iterations and become close to collinear. This last result suggests we could use the eigenvectors solution of a problem in a sequence as an educated guess for the eigenvectors of the successive problem. In this talk we present preliminary results that would eventually open the way to a widespread use of iterative solvers in ab initio electronic structure codes. We provide numerical examples where opportunely selected iterative solvers benefit from the reuse of eigenvectors when applied to sequences of eigenproblems extracted from simulations of real-world materials.
000021585 536__ $$0G:(DE-Juel1)FUEK411$$2G:(DE-HGF)$$aScientific Computing$$cP41$$x0
000021585 536__ $$0G:(DE-Juel1)SDLQM$$aSimulation and Data Laboratory Quantum Materials (SDLQM) (SDLQM)$$cSDLQM$$fSimulation and Data Laboratory Quantum Materials (SDLQM)$$x2
000021585 909CO $$ooai:juser.fz-juelich.de:21585$$pVDB
000021585 9131_ $$0G:(DE-Juel1)FUEK411$$1G:(DE-HGF)POF2-410$$2G:(DE-HGF)POF2-400$$bSchlüsseltechnologien$$kP41$$lSupercomputing$$vScientific Computing$$x0
000021585 9141_ $$y2012
000021585 9201_ $$0I:(DE-Juel1)JSC-20090406$$gJSC$$kJSC$$lJülich Supercomputing Centre$$x0
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