Results for Point Group D2h



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


Decomposition to irreducible representations
Motion A1g B1g B2g B3g A1u B1u B2u B3u Total
Cartesian 3N 4 3 3 2 1 4 3 4 24
Translation (x,y,z) 0 0 0 0 0 1 1 1 3
Rotation (Rx,Ry,Rz) 0 1 1 1 0 0 0 0 3
Vibration 4 2 2 1 1 3 2 3 18



Molecular parameter
Number of Atoms (N) 8
Number of internal coordinates 18
Number of independant internal coordinates 4
Number of vibrational modes 18


Force field analysis


Allowed / forbidden vibronational transitions
Operator A1g B1g B2g B3g A1u B1u B2u B3u Total
Linear (IR) 4 2 2 1 1 3 2 3 8 / 10
Quadratic (Raman) 4 2 2 1 1 3 2 3 9 / 9
IR + Raman - - - - - - - - - - - - - - - - 1 - - - - - - - - - - - - 0* / 1
* Parity Mutual Exclusion Principle


Characters of force fields
(Symmetric powers of vibration representation)
Force field E C2.(z) C2.(y) C2.(x) i σ.(xy) σ.(xy) σ.(xy)
linear 18 2 0 0 0 4 6 2
quadratic 171 11 9 9 9 17 27 11
cubic 1.140 20 0 0 0 48 92 20
quartic 5.985 65 45 45 45 133 273 65
quintic 26.334 110 0 0 0 308 714 110
sextic 100.947 275 165 165 165 693 1.715 275


Decomposition to irreducible representations
Column with number of nonvanshing force constants highlighted
Force field A1g B1g B2g B3g A1u B1u B2u B3u
linear 4 2 2 1 1 3 2 3
quadratic 33 19 21 17 17 22 19 23
cubic 165 137 143 125 125 153 137 155
quartic 832 725 755 703 703 765 725 777
quintic 3.447 3.241 3.315 3.164 3.164 3.370 3.241 3.392
sextic 13.050 12.470 12.698 12.338 12.338 12.753 12.470 12.830


Further Reading



Contributions to nonvanishing force field constants


pos(X) : Position of irreducible representation (irrep) X in character table of D2h

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(A1g) ≤ i ≤ pos(B3u)
..10. A1gA1g...3. B1gB1g...3. B2gB2g...1. B3gB3g...1. A1uA1u...6. B1uB1u...3. B2uB2u...6. B3uB3u.
Subtotal: 33 / 8 / 8
Irrep combinations (i,j) with indices: pos(A1g) ≤ i ≤ j ≤ pos(B3u)
Subtotal: 0 / 0 / 28
Total: 33 / 8 / 36


Contributions to nonvanishing cubic force field constants
Irrep combinations (i,i,i) with indices: pos(A1g) ≤ i ≤ pos(B3u)
..20. A1gA1gA1g.
Subtotal: 20 / 1 / 8
Irrep combinations (i,i,j) (i,j,j) with indices: pos(A1g) ≤ i ≤ j ≤ pos(B3u)
..12. A1gB1gB1g...12. A1gB2gB2g...4. A1gB3gB3g...4. A1gA1uA1u...24. A1gB1uB1u...12. A1gB2uB2u...24. A1gB3uB3u.
Subtotal: 92 / 7 / 56
Irrep combinations (i,j,k) with indices: pos(A1g) ≤ i ≤ j ≤ k ≤ pos(B3u)
..4. B1gB2gB3g...6. B1gA1uB1u...12. B1gB2uB3u...4. B2gA1uB2u...18. B2gB1uB3u...3. B3gA1uB3u...6. B3gB1uB2u.
Subtotal: 53 / 7 / 56
Total: 165 / 15 / 120


Contributions to nonvanishing quartic force field constants
Irrep combinations (i,i,i,i) with indices: pos(A1g) ≤ i ≤ pos(B3u)
..35. A1gA1gA1gA1g...5. B1gB1gB1gB1g...5. B2gB2gB2gB2g...1. B3gB3gB3gB3g...1. A1uA1uA1uA1u...15. B1uB1uB1uB1u...5. B2uB2uB2uB2u...15. B3uB3uB3uB3u.
Subtotal: 82 / 8 / 8
Irrep combinations (i,i,i,j) (i,j,j,j) with indices: pos(A1g) ≤ i ≤ j ≤ pos(B3u)
Subtotal: 0 / 0 / 56
Irrep combinations (i,i,j,j) with indices: pos(A1g) ≤ i ≤ j ≤ pos(B3u)
..30. A1gA1gB1gB1g...30. A1gA1gB2gB2g...10. A1gA1gB3gB3g...10. A1gA1gA1uA1u...60. A1gA1gB1uB1u...30. A1gA1gB2uB2u...60. A1gA1gB3uB3u...9. B1gB1gB2gB2g...3. B1gB1gB3gB3g...3. B1gB1gA1uA1u.
..18. B1gB1gB1uB1u...9. B1gB1gB2uB2u...18. B1gB1gB3uB3u...3. B2gB2gB3gB3g...3. B2gB2gA1uA1u...18. B2gB2gB1uB1u...9. B2gB2gB2uB2u...18. B2gB2gB3uB3u...1. B3gB3gA1uA1u...6. B3gB3gB1uB1u.
..3. B3gB3gB2uB2u...6. B3gB3gB3uB3u...6. A1uA1uB1uB1u...3. A1uA1uB2uB2u...6. A1uA1uB3uB3u...18. B1uB1uB2uB2u...36. B1uB1uB3uB3u...18. B2uB2uB3uB3u.
Subtotal: 444 / 28 / 28
Irrep combinations (i,i,j,k) (i,j,j,k) (i,j,k,k) with indices: pos(A1g) ≤ i ≤ j ≤ k ≤ pos(B3u)
Subtotal: 0 / 0 / 168
Irrep combinations (i,j,k,l) with indices: pos(A1g) ≤ i ≤ j ≤ k ≤ l ≤ pos(B3u)
..16. A1gB1gB2gB3g...24. A1gB1gA1uB1u...48. A1gB1gB2uB3u...16. A1gB2gA1uB2u...72. A1gB2gB1uB3u...12. A1gB3gA1uB3u...24. A1gB3gB1uB2u...12. B1gB2gA1uB3u...24. B1gB2gB1uB2u...4. B1gB3gA1uB2u.
..18. B1gB3gB1uB3u...6. B2gB3gA1uB1u...12. B2gB3gB2uB3u...18. A1uB1uB2uB3u.
Subtotal: 306 / 14 / 70
Total: 832 / 50 / 330


Calculate contributions to

A1g B1g B2g B3g A1u B1u B2u B3u
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Last update November, 13th 2023 by A. Gelessus, Impressum, Datenschutzerklärung/DataPrivacyStatement