考虑溶剂效应的紫外吸收光谱计算

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1、采用PCM模型计算溶液中的紫外吸收光谱ThePCMmethodinGaussian09includesanexternaliterationprocedurewherebytheprogramcomputestheenergyinsolutionbymakingthesolventreactionfieldself-consistentwiththesoluteelectrostaticpotential(thelatterbeinggeneratedfromthecomputedelectrondensitywiththespecifiedmode

2、lchemistry).Step1:Groundstategeometryoptimizationandfrequencies(equilibriumsolvation平衡溶剂化：在电子结构不发生改变时，若分子几何结构发生变化则溶剂也跟着变化). Thisisastandard OptFreqcalculationonthegroundstateincludingPCMequilibriumsolvation.获得溶剂中基态稳定几何结构，默认为Eq状态%chk=01-ac#B3LYP/6-31+G(d,p)OptFreqSCRF=(Solvent=E

3、thanol)Acetaldehydegroundstate01分子说明(请自行补充)Hereistheenergyofthegroundstateoptimizedgeometryinsolution:SCFDone:E(RB3LYP)=-153.851761719A.U.after1cyclesStep2:Verticalexcitationwithlinearresponsesolvation. 默认为Non-Eq过程ThisisaTD-DFTcalculationoftheverticalexcitation,thereforeatthegr

4、oundstateequilibriumgeometry,withthedefaultsolvation:linearresponse,non-equilibrium.Weperformasingle-pointTD-DFTcalculation,whichdefaultstonon-equilibriumsolvation.Theresultsofthisjobwillbeusedtoidentifywhichstateorstatesareofinterestandtheirordering.Theseresultsgiveareasonable

5、descriptionofthesolvationoftheexcitedstate,butnotquiteasgoodasthatfromastate-specificsolvationcalculation.Inthiscase,weseethatthen→π*state(产生第一激发态的跃迁方式)isthefirstexcitedstate.Next,wewillusethestate-specificmethodtoproduceabetterdescriptionoftheverticalexcitationstep.复制以上step1中的

6、01-ac.chk,并将复制文件命名为02-ac.chk，然后执行如下操作计算紫外跃迁吸收光谱。下边这个计算默认为non-equilibriumsolvation。垂直激发默认为NonEq过程，但此时没有使用EI%chk=02-ac#B3LYP/6-31+G(d,p)TD=NStates=6SCRF=(Solvent=Ethanol)Geom=CheckGuess=ReadAcetaldehyde:linearresponseverticalexcitedstates01Theverticalexcitation(absorption)tofirst

7、excitedstatefromthenon-equilibriumsolvationlinearresponsecalculation:发生电子跃迁时，溶剂来不及运动，所以叫做non-equilibriumsolvationlinearresponseExcitedState1:Singlet-A"4.3767eV283.28nmf=0.0000=0.000Thus,thegroundstatetofirstexcitedstateabsorptionisat283.28nm,computedviathelinear-responsea

8、pproach.Step3:State-specificsolvationoftheverticalexci