chatgpt

Calculate the first 2 excited states of the Oxygen atom by using the CASSCF method with appropriate basis sets then compare with the experimental values

	EXP	aug-cc-pVTZ	d-aug-cc-pVTZ	6-311G(2df,2pd)	6-311G(3pd,3df)	aug-cc-pVQZ
3P→1D	1.97	2.03	2.03	2.18	2.05	1.91
1D→1S	2.22	1.75	1.75	1.77	1.77	1.75

 使用更大的基底函數對於結果沒也甚麼太大的差異。

experimental value : NIST Atomic Spectra Database

 

•For 7-Azaindole there have normal form & tautomer form two different structures

methods : B3LYP/6-31G**

 

• Which one is more stable at ground state

  unit : Hartree 

ground state
normal form	Transition state	tautomer form
-379.87234	-379.76976	-379.85166

normal form is more stable

 

• Will there has Transition State ( TS ) between the two structures? If so, what would be the barrier height between them

 

excited state
normal form	Transition state	tautomer form
-379.70412	-379.63224	-379.75302

 

 

	ΔV≠(Hartree)	ΔV≠(kcal/mol)
ground state	0.10258	64.4
excited state	0.07188	45.1

 

•  Optimize the first excited state of two structures, and plot a simple energy level diagram based on the energy difference.
• Calculate the verticle excitation energy between the ground state & first excited state.