资源描述：
《towards a working density-functional theory for polymers first-principles determination ofnew》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。
1、Towardsaworkingdensity-functionaltheoryforpolymers:First-principlesdeterminationofthepolyethylenecrystalstructureJesperKleis,1BengtI.Lundqvist,1DavidC.Langreth,2andElsebethSchr¨oder11DepartmentofAppliedPhysics,ChalmersUniversityofTechnology,SE-41296G¨oteborg,Sweden2DepartmentofPhysicsand
2、Astronomy,RutgersUniversity,Piscataway,N.J.08854-8019(Dated:February5,2008)Equilibriumpolyethylenecrystalstructure,cohesiveenergy,andelasticconstantsarecalculatedbydensity-functionaltheoryappliedwitharecentlyproposeddensityfunctional(vdW-DF)forgeneralgeometries[Phys.Rev.Lett.92,246401(20
3、04)]andwithapseudopotential-planewavescheme.ThevdW-DFwithitsaccountforthelong-rangedvanderWaalsinteractionsgivesnotonlyastabilizedcrystalstructurebutalsovaluesofthecalculatedlatticeparametersandelasticconstantsinquitegoodagreementwithexperimentaldata,givingpromiseforsuccessfulapplication
4、toawiderrangeofpolymers.PACSnumbers:31.15.Ew,36.20.Hb,71.15.Mb,61.50.LtUnderstandingofcrystallinesolidsisgreatlyenhancedbothforceschemesandhybridmethods.bytheperiodicityoftheatomicstructure,whichallowsTheongoingDFTsuccessstoryforground-stateelec-verydetailedcomparisonsbetweentheoryandexp
5、eri-tronstructurecalculationsofdensematerialssystemsisment.Macromolecularmaterials,suchaspolymersanddrivenbytherelativelylowcomputationalcosttogetherothercomplexfluids,arelesswellunderstood,duetowiththeabilitytodescribeverydiversesystems.How-thechallengingcomplexnaturesoftheirstructures.F
6、ea-ever,thewidelyusedlocalandsemilocalimplementa-turesofthepolymerontheatomicandmesoscopiclengthtionsdonotincludelong-rangenonlocalcorrelationsthatscalesareinter-dependent.Forinstance,atomicbondsareessentialforaproperdescriptionoftheintermolecu-areonthe˚Angstr¨omscale,whilediffusionproces
7、sesin-larvdWinteractions.Theseinteractionsarecrucialforvolvewholechainsextendingsome100˚A.Inordertothestabilityofsystemswithregionsoflowelectronden-coverthefullsetoflengthscalesbytheoryweneedsity,oftenencounteredinbiologicalandnanotechnologi-atomic-scaleinputformesoscopic
