Results for Point Group Td



Characters of representations for molecular motions
Motion E 8C3 3C2 6S4 6σd
Cartesian 3N 24 0 0 0 4
Translation (x,y,z) 3 0 -1 -1 1
Rotation (Rx,Ry,Rz) 3 0 -1 1 -1
Vibration 18 0 2 0 4


Decomposition to irreducible representations
Motion A1 A2 E T1 T2 Total
Cartesian 3N 2 0 2 2 4 10
Translation (x,y,z) 0 0 0 0 1 1
Rotation (Rx,Ry,Rz) 0 0 0 1 0 1
Vibration 2 0 2 1 3 8



Molecular parameter
Number of Atoms (N) 8
Number of internal coordinates 18
Number of independant internal coordinates 2
Number of vibrational modes 8

Force field analysis


Allowed / forbidden vibronational transitions
Operator A1 A2 E T1 T2 Total
Linear (IR) 2 0 2 1 3 3 / 5
Quadratic (Raman) 2 0 2 1 3 7 / 1
IR + Raman - - - - 0 - - - - 1 3 3 / 1


Characters of force fields
(Symmetric powers of vibration representation)
Force field E 8C3 3C2 6S4 6σd
linear 18 0 2 0 4
quadratic 171 0 11 1 17
cubic 1.140 6 20 0 48
quartic 5.985 0 65 5 133
quintic 26.334 0 110 0 308
sextic 100.947 21 275 5 693


Decomposition to irreducible representations
Column with number of nonvanshing force constants highlighted
Force field A1 A2 E T1 T2
linear 2 0 2 1 3
quadratic 13 4 17 16 24
cubic 64 40 98 128 152
quartic 292 223 515 708 772
quintic 1.188 1.034 2.222 3.201 3.355
sextic 4.422 4.073 8.474 12.412 12.756


Further Reading


Contributions to nonvanishing force field constants


pos(X) : Position of irreducible representation (irrep) X in character table of Td

Subtotal: <Number of nonvanishing force constants in subsection> / <number of nonzero irrep combinations in subsection> / <number of irrep combinations in subsection>
Total: <Number of nonvanishing force constants in force field> / <number of nonzero irrep combinations in force field> / <number of irrep combinations in force field>


Contributions to nonvanishing quadratic force field constants
Irrep combinations (i,i) with indices: pos(A1) ≤ i ≤ pos(T2)
..3. A1A1...3. EE...1. T1T1...6. T2T2.
Subtotal: 13 / 4 / 5
Irrep combinations (i,j) with indices: pos(A1) ≤ i ≤ j ≤ pos(T2)
Subtotal: 0 / 0 / 10
Total: 13 / 4 / 15


Contributions to nonvanishing cubic force field constants
Irrep combinations (i,i,i) with indices: pos(A1) ≤ i ≤ pos(T2)
..4. A1A1A1...4. EEE...10. T2T2T2.
Subtotal: 18 / 3 / 5
Irrep combinations (i,i,j) (i,j,j) with indices: pos(A1) ≤ i ≤ j ≤ pos(T2)
..3. T1T1T2...6. A1EE...2. A1T1T1...12. A1T2T2...2. ET1T1...12. ET2T2...3. T1T2T2.
Subtotal: 40 / 7 / 20
Irrep combinations (i,j,k) with indices: pos(A1) ≤ i ≤ j ≤ k ≤ pos(T2)
..6. ET1T2.
Subtotal: 6 / 1 / 10
Total: 64 / 11 / 35


Contributions to nonvanishing quartic force field constants
Irrep combinations (i,i,i,i) with indices: pos(A1) ≤ i ≤ pos(T2)
..5. A1A1A1A1...6. EEEE...2. T1T1T1T1...36. T2T2T2T2.
Subtotal: 49 / 4 / 5
Irrep combinations (i,i,i,j) (i,j,j,j) with indices: pos(A1) ≤ i ≤ j ≤ pos(T2)
..3. T1T1T1T2...8. A1EEE...20. A1T2T2T2...16. ET2T2T2...18. T1T2T2T2.
Subtotal: 65 / 5 / 20
Irrep combinations (i,i,j,j) with indices: pos(A1) ≤ i ≤ j ≤ pos(T2)
..9. A1A1EE...3. A1A1T1T1...18. A1A1T2T2...6. EET1T1...36. EET2T2...18. T1T1T2T2.
Subtotal: 90 / 6 / 10
Irrep combinations (i,i,j,k) (i,j,j,k) (i,j,k,k) with indices: pos(A1) ≤ i ≤ j ≤ k ≤ pos(T2)
..12. EET1T2...6. A1T1T1T2...6. ET1T1T2...4. A1ET1T1...24. A1ET2T2...6. A1T1T2T2...18. ET1T2T2.
Subtotal: 76 / 7 / 30
Irrep combinations (i,j,k,l) with indices: pos(A1) ≤ i ≤ j ≤ k ≤ l ≤ pos(T2)
..12. A1ET1T2.
Subtotal: 12 / 1 / 5
Total: 292 / 23 / 70


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A1 A2 E T1 T2
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Last update November, 13th 2023 by A. Gelessus, Impressum, Datenschutzerklärung/DataPrivacyStatement