Actinium (Ac)
Energy Levels of Neutral Actinium ( Ac I )
Configuration
Term
J
Level(cm
-1
)
Ref.
6
d
7
s
2
2
D
3/2
0.00
MFT57
5/2
2231.43
MFT57
6
d
2
7
s
4
F
3/2
9217.28
MFT57
5/2
9863.59
MFT57
7/2
10906.02
MFT57
9/2
12078.07
MFT57
6
d
7
s
(
3
D)7
p
4
F°
3/2
13712.90
MFT57
5/2
14940.72
MFT57
7/2
17683.87
MFT57
6
d
7
s
(
3
D)7
p
4
D°
1/2
17199.71
MFT57
3/2
19012.46
MFT57
5/2
21195.87
MFT57
7/2
23475.94
MFT57
6
d
7
s
(
3
D)7
p
2
D°
3/2
17736.26
MFT57
5/2
17950.71
MFT57
6
d
7
s
(
3
D)7
p
4
P°
1/2
22401.52
MFT57
3/2
22801.10
MFT57
5/2
23898.86
MFT57
6
d
7
s
(
3
D)7
p
2
F°
5/2
23916.84
MFT57
7/2
24969.30
MFT57
6
d
7
s
(
3
D)7
p
2
P°
1/2
25729.03
MFT57
3/2
27009.84
MFT57
6
d
7
s
(
1
D)7
p
2
D°
3/2
26066.04
MFT57
5/2
26533.16
MFT57
6
d
7
s
(
1
D)7
p
2
F°
5/2
26836.20
MFT57
7/2
28568.40
MFT57
6
d
7
s
(
1
D)7
p
2
P°
3/2
30396.61
MFT57
6
d
2
(
3
F)7
p
4
G°
5/2
31494.68
MFT57
7/2
32219.62
MFT57
9/2
32867.39
MFT57
11/2
33429.76
MFT57
Ac II (
1
S
0
)
Limit
41700
S74