HW4
1. ChatGPT
2. Electron Affinity of Hydrogen and Helium
Electron Affinity(EA): IUPAC definition
X-→X+e-, EA = E(X) - E(X-)
Electron Affinity:
|
H |
(unit: kcal/mol) |
MP2 |
B3LYP |
M062X |
He |
(unit: kcal/mol) |
MP2 |
B3LYP |
M062X |
|
|
6-31G** |
39.43 |
24.1 |
29.8 |
|
6-31G** |
-860.6 |
-829.8 |
-827.8 |
|
|
6-311G** |
10.6 |
4.8 |
0.1 |
|
6-311G** |
-514.6 |
-493.1 |
-482.7 |
|
|
6-31++G** |
3.0 |
20.4 |
13.4 |
|
6-31++G** |
-127.9 |
-117.3 |
-114.4 |
|
|
6-311++G** |
3.6 |
20.0 |
13.3 |
|
6-311++G** |
-116.5 |
-105.9 |
-104.3 |
實驗值:
|
實驗值a(kcal/mol) |
|
|
H |
17.4 |
|
He |
-5.0 |
a: Atkins' PHYSICAL CHEMISTRY 10th Ed, page 984
絕對誤差:
My choice:
Hydrogen: B3LYP/6-31++G** or B3LYP/6-311++G**
Helium: 6-31++G** or 6-311++G**
3. Electron Affinity of atoms with atomic number 3~18
實驗值:
|
實驗值a(kcal/mol) |
|
|
Li |
14.3 |
|
Be |
0.0 |
|
B |
5.5 |
|
C |
29.3 |
|
N |
-1.7 |
|
O |
33.7 |
|
F |
77.0 |
|
Ne |
-6.9 |
|
Na |
12.6 |
|
Mg |
0.0 |
|
Al |
10.5 |
|
Si |
31.9 |
|
P |
17.1 |
|
S |
47.9 |
|
Cl |
83.3 |
|
Ar |
-8.4 |
相同基底函數，不同方法的絕對誤差比較
B3LYP/6-311+G** is more accurate.
Reference:
https://gaussian.com/scf/
https://cccbdb.nist.gov/elecaff1x.asp