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[求助] Gaussian 09 中溶剂化的荧光发射

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在Gaussian 09 的计算荧光发射考虑了溶剂化效应的算例中（如下所示），在7步计算中，各自读取的chk文件分别是哪个啊？还有就是具体的“平衡溶解”和“非平衡溶解”是什么意思？

谢谢指导，苦恼了好几天的一个问题了，拿出来大家讨论一下
Fluoresence example: Emission (Fluorescence) from First Excited State (n→π*) of Acetaldehyde

Here we study the cycle:

Acetaldehyde Excitation and Emission Cycle

The primary process of interest is the emission, but this example shows how to study the complete cycle including the solvent effects.
Step 1: Ground state geometry optimization and frequencies (equilibrium solvation). This is a standard Opt Freq calculation on the ground state including PCM equilibrium solvation.

%chk=01-ac
# B3LYP/6-31+G(d,p) Opt Freq SCRF=(Solvent=Ethanol)

Acetaldehyde ground state

0 1
C
C,1,RA
X,2,1.,1,A
O,2,RB,3,A,1,180.,0
X,1,1.,2,90.,3,0.,0
H,1,R1,2,A1,5,0.,0
H,1,R23,2,A23,5,B23,0
H,1,R23,2,A23,5,-B23,0
H,2,R4,1,A4,3,180.,0

RA=1.53643
RB=1.21718
R1=1.08516
R23=1.08688
R4=1.10433
A=62.1511
A1=110.51212
A23=109.88119
A4=114.26114
B23=120.56468

Step 2: Vertical excitation with linear response solvation. This is a TD-DFT calculation of the vertical excitation, therefore at the ground state equilibrium geometry, with the default solvation: linear response, non-equilibrium. We perform a single-point TD-DFT calculation, which defaults to non-equilibrium solvation. The results of this job will be used to identify which state or states are of interest and their ordering. These results give a reasonable description of the solvation of the excited state, but not quite as good as that from a state-specific solvation calculation. In this case, we see that the n->π* state is the first excited state. Next, we will use the state-specific method to produce a better description of the vertical excitation step.

%chk=02-ac
# B3LYP/6-31+G(d,p) TD=NStates=6 SCRF=(Solvent=Ethanol)
  Geom=Check Guess=Read

Acetaldehyde: linear response vertical excited states

0 1

Step 3: State-specific solvation of the vertical excitation. This will require two job steps: first the ground state calculation is done, specifying NonEq=write in the PCM input section, in order to store the information about non-equilibrium solvation based on the ground state. Second, the actual state-specific calculation is done, reading in the necessary information for non-equilibrium solvation using NonEq=read.

%chk=03-ac
# B3LYP/6-31+G(d,p) SCRF=(Solvent=Ethanol,Read)
  Geom=Check Guess=Read

Acetaldehyde: prepare for state-specific non-eq solvation
by saving the solvent reaction field from the ground state

0 1

NonEq=write

--link1--
%chk=03-ac
# B3LYP/6-31+G(d,p) TD(NStates=6,Root=1)
  SCRF=(Solvent=Ethanol,StateSpecific,Read)
  Geom=Check Guess=Read

Acetaldehyde: read non-eq solvation from ground state and
compute energy of the first excited with the state-specific method

0 1

NonEq=read

Step 4: Relaxation of the excited state geometry. Next, we perform a TD-DFT geometry optimization, with equilibrium, linear response solvation, in order to find the minimum energy point on the excited state potential energy surface. Since this is a TD-DFT optimization, the program defaults to equilibrium solvation. As is typical of such cases, the molecule has a plane of symmetry in the ground state but the symmetry is broken in the excited state, so the ground state geometry is perturbed slightly to break symmetry at the start of the optimization.

%chk=04-ac
# B3LYP/6-31+G(d,p) TD=(Read,NStates=6,Root=1) SCRF=(Solvent=Ethanol)
  Geom=Modify Guess=Read Opt=RCFC

Acetaldehyde: excited state opt
Modify geometry to break Cs symmetry
since first excited state is A"

0 1

4 1 2 3 10.0
5 1 2 7 -50.0

Step 5: Vibrational frequencies of the excited state structure. Now we run a frequency calculation to verify that the geometry located in step 4 is a minimum. The results could also be used as part of a Franck-Condon calculation if desired (see below). This is a numerical frequency calculation.

%chk=05-ac
# B3LYP/6-31+G(d,p) TD=(Read,NStates=6,Root=1) Freq
  SCRF=(Solvent=Ethanol) Geom=Check Guess=Read

Acetaldehyde excited state freq

0 1

Step 6: Emission state-specific solvation (part 1). This step does state-specific equilibrium solvation of the excited state at its equilibrium geometry, writing out the solvation data for the next step via the PCM NonEq=write input.

%chk=06-ac
# B3LYP/6-31+G(d,p) TD=(Read,NStates=6,Root=1)
  SCRF=(Solvent=Ethanol,StateSpecific,Read)
  Geom=Check Guess=Read

Acetaldehyde emission state-specific solvation
at first excited state optimized geometry

0 1

NonEq=write

Step 7: Emission to final ground state (part 2). Finally, we compute the ground state energy with non-equibrium solvation, at the excited state geometry and with the static solvation from the excited state.

%chk=07-ac
# B3LYP/6-31+G(d,p) SCRF=(Solvent=Ethanol,Read) Geom=Check Guess=Read

Acetaldehyde: ground state non-equilibrium
at excited state geometry.

0 1

NonEq=read

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1楼2011-08-23 15:22:51

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引用回帖:

2楼: Originally posted by hairan at 2011-08-23 18:07:34:
每一步计算分别使用前一步计算保存的chk文件，所以从第二个计算开始时，你需要手动将前一个计算chk文件复制一下，名字为新的计算的chk文件名。

关于平衡性和费平衡性计算主要是涉及使用溶剂模型的激发态计算， ...

还行向您咨询一下，就是第5部只是激发态的频率分析计算，起辅助作用，所以，第6步是不是应该读取的是第4步的chk文件？
相应的，第3步是不是应该先读第1步的chk文件，因为它前半部分进行的是基态的非平衡单点计算，说是保存了非平衡的溶剂反应场，这一点也不是很明白，求解答。
第6步和7步具体是什么关系？第6步已经做了激发态的发射，第7步做的是激发态结构的单点吗？6和7合起来好像和步骤3的两部分是相照应的，真的是晕了

谢谢，苦恼了好多天，解决后不胜感激