Energy levels of Li
+
(3l3l
’
)
“
Molecular
”
picture
“
Atomic
”
picture
Hund
’
s rule
E~E
N
+
ω
(v+1)+B[L(L+1)-T
2
]+GT
2
1
S
e
1
S
e
n=1
n=2
n=0
1
P
o
1
P
o
3
P
e
1
D
e
3
P
e
1
D
e
1
F
o
1
G
e
1
F
o
1
G
e
3
F
e
3
P
o
1
D
e
1
S
e
1
D
e
3
D
o
3
D
e
3
F
e
3
D
e
1
S
e
1
D
o
1
D
o
3
F
o
1
P
o
3
P
e
3
F
o
1
D
e
n=(v-T)/2
3
P
e
1
P
o
3
P
o
3
P
o
1
S
e
1
D
e
v=N-K-1
1
S
e
T
2
1
0
1
2
1
0
1
0
3s3s
3s3
p
3s3d
3p3p
3p3
d
3d3d