• Electron Affinity(EA): IUPAC定義

  X^-→X+e^-, EA = E(X) - E(X^-)

• Electron affinity & Absolute error ( unit: kcal/mol )
  • Basis sets : 6-31G**, 6-31+G**, 6-311G**, 6-311+G**
  • Theories : MP2, B3LYP, M062X

Excel

Reference : Atkins' PHYSICAL CHEMISTRY 10th Ed

MAE	MP2	B3LYP	M062X	Avg
6-31G**	36.5	24.8	26.8	29.4
6-31+G**	15.6	7.3	8.0	10.3
6-311G**	24.7	14.2	15.9	18.3
6-311+G**	13.4	5.5	16.2	11.7
Avg	22.6	13.0	16.7

• In MP2 theory, our basis set use 6-31G** > 6-311G** > 6-31+G** > 6-311+G**
• In B3LYP theory, our basis set use 6-31G** > 6-311G** > 6-31+G** > 6-311+G**
• In M062X theory, our basis set use 6-31G** > 6-311+G** > 6-311G** > 6-31+G** 

                                                                             (bad->good)

• Use diffuse functions has more accuracy 

 

 

 

Hydrogen and Helium, Electron affinity & Absolute error ( unit: kcal/mol )

電子親和力(atom-anion)		單位:kcal/mol
H	MP2	B3LYP	M062X	exp
6-31++G**	3.0	20.5	13.4	17.3992
6-311++G**	3.6	20.0	13.3
6-31G**	-39.4	-24.1	-29.8
6-311G**	-10.6	4.8	-0.1

電子親和力(atom-anion)		單位:kcal/mol
He	MP2	B3LYP	M062X	exp
6-31++G**	-127.9	-117.4	-114.5	-5.019
6-311++G**	-116.6	-106.0	-104.4
6-31G**	-860.6	-829.9	-827.9
6-311G**	-514.7	-493.2	-482.7

• For H we prefer use B3LYP/6-31++G**，B3LYP/6-311++G**

 

 

• Ionization energy

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