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12 个结果
  • 简介:ThereactionofsingletoxygenwithethylenehasbeenstudiedattheabinitiolevelwithbothHF/3-21GandHF/6-31Gbasissets,fullyoptimizingthegeometriesofthecriticalpoints.Thetransitionstateleadingtotheintermediateperoxiranefromtheinitialreactantsisfound,Iocatedat81.71kJ/molabovethedissociationlimit.Thevibrationalanalysisisdonewithtwobasissets.Fromtheresultsitcanbeseenthatthefrequencieshavenotbeenmadeanimprovementobviouslywithaugmented6-31Gcomparedto3-21Gbasis;itfollowsthatmainreasonfortoohighHF/3-21Gfrequencycouldmainlybethevibrationalanharmonicity.TheeigenvectorcorrespondingtothesingleimaginaryvibrationalfrequencyisdominatedbythelargerO-Odistance.Thefindingofthetransitionstateconfirmsthattheperoxiraneminimumcanbereachablepassingthroughaperoxirane-likesaddlepoint.Inaddition,themechanismsofthereactionformingoxiranearediscussedaswell.

  • 标签: Ab INITIO SINGLET OXYGEN ETHYLENE peroxirane
  • 简介:Sphere-likecompoundC8H17Si(OPhC12H25)3N(1)formsmesophases.Inordertoinvestigatetherelationshipbetweenmolecularstructureandliquidcrystalproperties,structuralstudiesarecarriedoutonthemodelmoleculesofcompound1anditssubstitutedderivativesusingahinitiocalculations.TheresultsshowthatthecyanoorchlorosubstitutedtribenzosilatranecompoundsR1Si(OPhR2)3N(R1R2=CNorCl)havemuchbiggerdipolemomentsoranisotropyofpolarizabilityandmorelikespherethanthecorrespondingalkylsubstitutedcompounds.Cyanoorchlorosubstitutedtribenzosilatraneswouldbebettercandidatesforsphere-likemeso-gens.

  • 标签: Sphere-like MESOGEN tribenzeosilatrane ab INITIO CALCULATION
  • 简介:在铝的氢的散开过程融化被分子的动力学调查模拟。对关联功能,第一个山峰位置,和协作数字被计算,在在Al-H,Cl-H,和Al-Cl对之中的结构的性质的差别被检验。改进氢散开上的氯的机制被讨论。从abinitio分子的动力学计算,在液体铝的氢的扩散性作为D(T)=(0.118

  • 标签: 分子动力学模拟 扩散过程 氢扩散 铝熔体 分子动力学计算 从头算
  • 简介:基于密度,功能的理论(DFT)和投影机扩充了的精力充沛的计算挥动的Abinitio为决定lanthanidesesquioxidesLn_2O_3的多型性的方法(爪)(在哪儿行=稀土元素的元素,Y,和Sc),LnMO_3perovskites(在哪儿M=AlandGa),并且Ln_2B_2O_7pyrochlores(在哪儿B=Ti,Zr,和Hf)被报导。除了theC类型Ln_2O_3,相对latticest能力与立方的结构,计算全部的精力为是更加更否定的与非常估计的结果或试验性的结果同意了很好。随Ln~(3+)阳离子半径的增加,多态的结构显示出果汁饮料生产趋势。第三的氧化物陶艺的形成的热含量的趋势和数量从他们相当适合于的成分二进制代码氧化物综合了可得到的试验性的结果,和珍贵热力学的性质被负担得起到化合物,没有试验性的数据为是可得到的。两perovskitesandpyrochlores的形成的热含量趋于随Ln~(3+)阳离子半径的增加变得更否定。

  • 标签: 稀土金属 氧化物陶瓷 从头计算 晶格稳定性 生成焓
  • 简介:选用aug-cc-pVTZ及aug-cc-pVQZ基组对不同H2-H2位形进行了量子化学计算,外推出了氢分子间各向异性ab-initio作用势。依据实验数据确定出氢分子相互作用的5-体模型,在全局最优算法基础上拟合出了包含电四极矩项、多体极化作用项及三体关联项等在内的氢分子间各向异性作用势。结果验证了拟合势与ab-initio势能曲线几乎重合,两者偏差落在(-1.35K,1.29K)范围内;得出的氢分子第二维里系数与实验结果一致。

  • 标签: 氢分子 各向异性作用势 从头计算
  • 简介:TheelectronicstructuresofCuS2,CuSe2andCuTe2withpyritestructures,withintheframeworkthedensity-functionaltheoryhavebeeninvestigated.ThecalculatedresultsexplainedtherecentexperimentalresultswhichshowthatthereisnoclearindicationofstrongelectroncorrelationsintheelectronicpropertiesofCupyrites,duetothedominantchalcogenpcharacterratherthandcharacteristicofCuattheFermilevel.

  • 标签: 从头算 黄铜矿 电子结构 CuS2 CuSe2 CuTe2
  • 简介:Thispapercarriesoutabinitiocalculationstostudythe80Se2(X3Σg-)stateand80Se2(X2Πg),80Se2(a4Πg)statesbyusingcompletedactivespaceself-consistentfieldandmulti-referencesecondorderperturbationtheory.Theelectroniccurvesofthesestatesincludingspin-orbitcouplingarecalculated,andthenthespectroscopicparametersareobtained.Thephotoelectronspectraof80Se2moleculeingasphaseareassignedaccordingtoFranck-Condonanalysisbasedoncalculatedpotentialenergycurves.Theionizationenergiesof80Se2moleculearedeterminedbythepresentcalculation.

  • 标签: 自旋轨道耦合 离子化能量 势能曲线图 Franck-Condon因数
  • 简介:Theabinitiogeneralizedgradientapproximation(GGA)+Ustudyofmultiferroic(La0.5Bi0.5)2FeCrO6inpnmastructureandferri-magneticorder,includingHubbardcorrections(U-4.1eV)fortransitionmetal/rareearthd-electronswith20atomscell,showsoptimumlocalmagneticmomentsof(Cr^3+,Fe^3+)equalto(-2.56,4.14)#Bandanidealspin-downbandgapof1.54eV.Tuned-bandgapLa-substituteddoubleoxideperovskitesBFCOshouldexhibitenhancedvisible-lightabsorptionandcarriermobility,thuscouldbeconvenientlightabsorbersandthenefficientalternativestowide-gapchalcopyriteabsorber-basedsolarcellsfailingtoachievehighestpowerconversionefficiencies,andevencompetewiththeirmetal-organichalideperovskitescounterparts.

  • 标签: OPTIMAL Bandgap Double Perovskite La-Substituted Bi2FeCrO6
  • 简介:AbinitiomolecularorbitalcalculationsofdoublynegativechargedB16H162-(D2)andneutralB16H16(Td)havebeendoneattheHF/6-31Glevel.TheyarepredictedtobechemicallyandkineticallystablebyvibrationalanalysesontheirrespectiveenergyhypersurfaceoftheHF/6-31Glevel.ThegeometricalstructureofthespeciesB16H1622-(D2)wasdiscussed.

  • 标签: Closo BORON hydrides ab INITIO MOLECULAR