TD计算结果疑问，HOMO~LUMO能隙比Homo-1~lumo能隙还大

ZHANGZY

  %chk=TD1-NP-acetonitrile.chk
%mem=3600MB
%nproc=4
Will use up to    4 processors via shared memory.
----------------------------------------------------------------------
#P TD(singlet, Nstates=30) O3LYP/6-31g(d) scrf=(solvent=acetonitrile,p
cm) nosymm geom=connectivity scf=(maxcycle=80,xqc) test


Excitation energies and oscillator strengths:

Excited state symmetry could not be determined.
Excited State   1:      Singlet-?Sym    3.4900 eV  355.26 nm  f=0.0001  <S**2>=0.000
      50 -> 52         0.70417
This state for optimization and/or second-order correction.
Total Energy, E(TD-HF/TD-DFT) =  -666.408605689   
Copying the excited state density for this state as the 1-particle RhoCI density.

Excited state symmetry could not be determined.
Excited State   2:      Singlet-?Sym    3.5890 eV  345.45 nm  f=0.2090  <S**2>=0.000
      51 -> 52         0.69724


版本（g16）TD计算结果疑问，HOMO~LUMO能隙比Homo-1~lumo能隙还大，这不合理！！，盼高手解释。

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i你贴的这里面哪里有HOMO、LUMO？

ZHANGZY

Excited State   1
50 -> 52 是 homo-1 ->lumo 能隙小3.4900 eV
Excited State   2
51 -> 52是 homo ->lumo 能隙大 3.5890 eV

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ZHANGZY 发表于 2018-8-24 09:42
Excited State   1
50 -> 52 是 homo-1 ->lumo 能隙小3.4900 eV
Excited State   2

激发能与这里所谓的Gap之间没有联系。之间还存在一个激子束缚能的概念。所以即便是H->L的跃迁，激发能也不会等于H->L的gap。具体公式请看：
http://bbs.keinsci.com/thread-188-1-1.html