Water graphene binding energy curve from diffusion Monte.ppt

WatergraphenebindingenergycurvefromdiffusionMonteCarloDepartmentofEarthSciences&DepartmentofPhysicsandAstronomy,******@UCL&LondonCentreforNanotechnologyUniversityCollegeLondonDarioALFÈAngelosMichaelides,JieMa,EngeWangMotivationWater-carbon(suchasgraphene,graphiteandcarbonnanotubes)interactionscrucialtounderstandphenomenasuchaslubrication,heterogeneousicenucleation,waterformationoninterstellardustgrain,structuralandphasebehaviourofwateratthenanoscale,,--:adsorptionofwaterquicklyresultsinwaterclustersTheory:Quantumchemistry(SD(T),SAPT…)onlyavailableonclusters;adsorptionenergyandgeometryneedtobeextrapolatedfromacenesofvarioussizes,resultsinrange100-,withpredictionsfromrepulsion(BLYP,B3LYP,revPBE)tobindingenergyof150meV(LDA).,,113,10242(2009);Estimatedbindingenergyis~90meV(SAPT)Water-graphenebindingcurvefromDFT“Twoleg”~10meVmorestablethan“Oneleg”withLDA(4meVwithPBE)Water-BenzenebindingcurveQMCtechnicaldetailsCASINOcode:,,,-Rios,CASINOusermanual,,UniversityofCambridge,(TrailandNeeds,,014112(2005);ibid122,174109(2005);seealsoCASINOweb-page)SingleparticleorbitalsfromPWSCF(planewaves),-splines.(è ,,70,161101(R),(2004))Water-,è,,,JCP,130,154303(2009)Water-benzenebindingenergy:NodaleffectsOrbitalsifrom:LDAB3LYPPBEPBE0HFBestisLDAWater-graphenebindingcurve“Twoleg”~10meVmorestablethan“Oneleg”withLDA(4meVwithPBE)