Point Group C18



C18 E C18 C9 C6 (C9)2 (C18)5 C3 (C18)7 (C9)4 C2 (C9)5 (C18)11 (C3)2 (C18)13 (C9)7 (C6)5 (C9)8 (C18)17
A 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
B 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1 -1
E1* 2 2cos(π/9) 2cos(2π/9) 1 2cos(4π/9) -2cos(4π/9) -1 -2cos(2π/9) -2cos(π/9) -2 -2cos(π/9) -2cos(2π/9) -1 -2cos(4π/9) 2cos(4π/9) 1 2cos(2π/9) 2cos(π/9)
E2* 2 2cos(2π/9) 2cos(4π/9) -1 -2cos(π/9) -2cos(π/9) -1 2cos(4π/9) 2cos(2π/9) 2 2cos(2π/9) 2cos(4π/9) -1 -2cos(π/9) -2cos(π/9) -1 2cos(4π/9) 2cos(2π/9)
E3* 2 1 -1 -2 -1 1 2 1 -1 -2 -1 1 2 1 -1 -2 -1 1
E4* 2 2cos(4π/9) -2cos(π/9) -1 2cos(2π/9) 2cos(2π/9) -1 -2cos(π/9) 2cos(4π/9) 2 2cos(4π/9) -2cos(π/9) -1 2cos(2π/9) 2cos(2π/9) -1 -2cos(π/9) 2cos(4π/9)
E5* 2 -2cos(4π/9) -2cos(π/9) 1 2cos(2π/9) -2cos(2π/9) -1 2cos(π/9) 2cos(4π/9) -2 2cos(4π/9) 2cos(π/9) -1 -2cos(2π/9) 2cos(2π/9) 1 -2cos(π/9) -2cos(4π/9)
E6* 2 -1 -1 2 -1 -1 2 -1 -1 2 -1 -1 2 -1 -1 2 -1 -1
E7* 2 -2cos(2π/9) 2cos(4π/9) 1 -2cos(π/9) 2cos(π/9) -1 -2cos(4π/9) 2cos(2π/9) -2 2cos(2π/9) -2cos(4π/9) -1 2cos(π/9) -2cos(π/9) 1 2cos(4π/9) -2cos(2π/9)
E8* 2 -2cos(π/9) 2cos(2π/9) -1 2cos(4π/9) 2cos(4π/9) -1 2cos(2π/9) -2cos(π/9) 2 -2cos(π/9) 2cos(2π/9) -1 2cos(4π/9) 2cos(4π/9) -1 2cos(2π/9) -2cos(π/9)


Additional information

Number of symmetry elements h = 18
Number of classes, irreps n = 18
Number of real-valued irreducible representations n = 10
Abelian group yes
Optical Isomerism (Chirality) yes
Polar yes
Parity no


Reduce representation to irreducible representations


E C18 C9 C6 (C9)2 (C18)5 C3 (C18)7 (C9)4 C2 (C9)5 (C18)11 (C3)2 (C18)13 (C9)7 (C6)5 (C9)8 (C18)17



Genrate representation from irreducible representations


A B E1* E2* E3* E4* E5* E6* E7* E8*




Direct products of irreducible representations


Binary products
A B E1* E2* E3* E4* E5* E6* E7* E8*
A A
B BA
E1* E1E82A⊕E2
E2* E2E7E1⊕E32A⊕E4
E3* E3E6E2⊕E4E1⊕E52A⊕E6
E4* E4E5E3⊕E5E2⊕E6E1⊕E72A⊕E8
E5* E5E4E4⊕E6E3⊕E7E2⊕E82B⊕E12A⊕E8
E6* E6E3E5⊕E7E4⊕E82B⊕E3E2⊕E8E1⊕E72A⊕E6
E7* E7E2E6⊕E82B⊕E5E4⊕E8E3⊕E7E2⊕E6E1⊕E52A⊕E4
E8* E8E12B⊕E7E6⊕E8E5⊕E7E4⊕E6E3⊕E5E2⊕E4E1⊕E32A⊕E2

Ternary Products
Quaternary Products



Symmetric powers [Γn] of degenerate irreducible representations
Vibrational overtones


irrep 2] 3] 4] 5] 6]
E1* A⊕E2E1⊕E3A⊕E2⊕E4E1⊕E3⊕E5A⊕E2⊕E4⊕E6More
E2* A⊕E4E2⊕E6A⊕E4⊕E8E2⊕E6⊕E8A⊕E4⊕E6⊕E8More
E3* A⊕E62B⊕E3A⊕2E62B⊕2E33A⊕2E6More
E4* A⊕E8E4⊕E6A⊕E2⊕E8E2⊕E4⊕E6A⊕E2⊕E6⊕E8More
E5* A⊕E8E3⊕E5A⊕E2⊕E8E3⊕E5⊕E7A⊕E2⊕E6⊕E8More
E6* A⊕E62A⊕E6A⊕2E62A⊕2E63A⊕2E6More
E7* A⊕E4E3⊕E7A⊕E4⊕E8E1⊕E3⊕E7A⊕E4⊕E6⊕E8More
E8* A⊕E2E6⊕E8A⊕E2⊕E4E4⊕E6⊕E8A⊕E2⊕E4⊕E6More



Spherical harmonics and Multipoles
Symmetric Powers of Γxyz


Spherical Harmonics Yl / Multipole Symmetric Power [Γl(xyz)]
l 2l+1 Multipole Symmetry Rank l(xyz)]
s (l=0) 1 Monopole A 1 A
p (l=1) 3 Dipole A⊕E1 3 A⊕E1
d (l=2) 5 Quadrupole A⊕E1⊕E2 6 2A⊕E1⊕E2
f (l=3) 7 Octupole A⊕E1⊕E2⊕E3 10 2A⊕2E1⊕E2⊕E3
g (l=4) 9 Hexadecapole A⊕E1⊕E2⊕E3⊕E4 15 3A⊕2E1⊕2E2⊕E3⊕E4
h (l=5) 11 Dotricontapole A⊕E1⊕E2⊕E3⊕E4⊕E5 21 3A⊕3E1⊕2E2⊕2E3⊕E4⊕E5
i (l=6) 13 Tetrahexacontapole A⊕E1⊕E2⊕E3⊕E4⊕E5⊕E6 28 4A⊕3E1⊕3E2⊕2E3⊕2E4⊕E5⊕E6
j (l=7) 15 Octacosahectapole A⊕E1⊕E2⊕E3⊕E4⊕E5⊕E6⊕E7 36 4A⊕4E1⊕3E2⊕3E3⊕2E4⊕2E5⊕E6⊕E7
k (l=8) 17 256-pole A⊕E1⊕E2⊕E3⊕E4⊕E5⊕E6⊕E7⊕E8 45 5A⊕4E1⊕4E2⊕3E3⊕3E4⊕2E5⊕2E6⊕E7⊕E8
l (l=9) 19 512-pole A⊕2B⊕E1⊕E2⊕E3⊕E4⊕E5⊕E6⊕E7⊕E8 55 5A⊕2B⊕5E1⊕4E2⊕4E3⊕3E4⊕3E5⊕2E6⊕2E7⊕E8
m (l=10) 21 1024-pole A⊕2B⊕E1⊕E2⊕E3⊕E4⊕E5⊕E6⊕E7⊕2E8 66 6A⊕2B⊕5E1⊕5E2⊕4E3⊕4E4⊕3E5⊕3E6⊕2E7⊕3E8
n (l=11) 23 2048-pole A⊕2B⊕E1⊕E2⊕E3⊕E4⊕E5⊕E6⊕2E7⊕2E8 78 6A⊕4B⊕6E1⊕5E2⊕5E3⊕4E4⊕4E5⊕3E6⊕4E7⊕3E8
o (l=12) 25 4096-pole A⊕2B⊕E1⊕E2⊕E3⊕E4⊕E5⊕2E6⊕2E7⊕2E8 91 7A⊕4B⊕6E1⊕6E2⊕5E3⊕5E4⊕4E5⊕5E6⊕4E7⊕5E8
More

First nonvanshing multipole: Dipole

Further Reading

  • A. Gelessus, W. Thiel, W. Weber. J. Chem. Educ. 72 505 (1995)
    Multipoles and symmetry




Ligand Field, dn term splitting


Term symbols for electronic configurations dn
dn Term Symbols
d1 = d9 2D
d2 = d8 1S, 1D, 1G, 3P, 3F
d3 = d7 2P, 2D (2), 2F, 2G, 2H, 4P, 4F
d4 = d6 1S (2), 1D (2), 1F, 1G (2), 1I, 3P (2), 3D, 3F (2), 3G, 3H, 5D
d5 2S, 2P, 2D (3), 2F (2), 2G (2), 2H, 2I, 4P, 4D, 4F, 4G, 6S


Term splitting in point group C18
L 2L+1 Term Splitting
S (L=0) 1 A
P (L=1) 3 A⊕E1
D (L=2) 5 A⊕E1⊕E2
F (L=3) 7 A⊕E1⊕E2⊕E3
G (L=4) 9 A⊕E1⊕E2⊕E3⊕E4
H (L=5) 11 A⊕E1⊕E2⊕E3⊕E4⊕E5
I (L=6) 13 A⊕E1⊕E2⊕E3⊕E4⊕E5⊕E6


Last update August, 12th 2020 by A. Gelessus, Impressum, Datenschutzerklärung/DataPrivacyStatement