Table 5.4
Independent nonzero dipole (l), quadrupole (H), octopole (X) and hexadecapole (U) electric moments (all values are in a.u.)
a
Molecule
Bond length
Basis set
a
l
z
H zz
X zzz
U zzzz
H
2
r
HH = 1.4487
aV5Z
–
–
0.48
b
0.46
[69]
–
–
0.32
b
0.31
[70]
O
2
r
OO = 2.29
aVQZ
–
–
−0.21
b
−0.3(1) [71]
–
–
4.67
b
4.48
[72]
N
2
r
NN = 2.1066
aV5Z
–
–
−1.08
b
−1.09 [73]
–
–
-6.81
b
−6.75 [56]
CO
2
r
CO = 2.2117
aV5Z
–
–
−3.15
b
−3.12 [74]
–
–
−2.08
b
−1.7 [75]
CO
r
CO = 2.1322
aV5Z
0.046
b
0.048
[76]
−1.46
b
−1.44 [77]
3.54
b
4.15
[78]
−8.96
b
−8.15 [78]
CN
r
CN = 2.21
aVQZ
0.560
b
0.57
[79]
0.42
b
1.21
b
−2.76
b
HCl
r
HCl = 2.41
aV5Z
0.432
b
0.436
[80]
2.69
b
2.78
[81]
3.99
b
4.17
[44]
13.56
b
14.3
[44]
HCN
r
CH = 2.0135
r
CN = 2.1792
aV5Z
−1.188
b
−1.18 [82]
1.70
b
1.65
[82]
−9.82
b
−9.76 [82]
23.27
b
22.45
[82]
NaCl
r
NaCl = 4.4613
awCVQZ
−3.537
b
−3.53 [83]
6.14
b
6.26
[84]
−19.40
b
−20.30 [84]
47.90
b
50.33
[84]
OH
r
OH = 1.8502
aV5Z
−0.649
b
−0.656 [85]
1.29
b
1.28
[86]
−2.35
b
−2.39 [86]
4.99
b
5.10
[86]
N
2 H
+
r
NH = 1.9551
r
NN = 2.0649
aVQZ
−1.070
b
4.41
−14.25
b
37.66
b
CH
4
r
CH
¼ 2:0674
aVQZ
–
–
–
2.65
c
2.41
c
[87]
−7.93
b
−7.69 [87]
a
For molecules CO, CN, HCl, HCN, NaCl, OH, N
2 H
+
the axis z
is directed to the atoms O, C, H, N, Cl, O, and N, respectively. The positive value of CO
dipole moment corresponds to its direction from C
−
to O
+
b
Calculated in Ref. [88] using the (R)CCSD(T)/aVXZ method (X = Q, 5, see the column 3 for the X value)
c
X xyz for CH
4
94
5 Interaction-induced Hyperpolarizability