Normal modes of the Caae conformer of RDX. Table includes plots of the activity of various internal degrees of freedom, as well as an mpeg animation of the respective eigenmode.

Forcefield by Boyd, Politzer and Gravelle

Experimental results

Computational results

Rey-Lafon, Trinquecoste, Cavagnat, Forel,

Chim Phys Chem Biol 68, 1533 (1971).

Sewell, Thompson, JCP99, 2661, 1993

Rice, Chabalowski, JPC101, 8720, 1997

description

Projection of mode onto degrees of freedom

Active degrees of freedom

k(cm^-1)

mpeg

IR

Raman

MM forcefield

DFT

NO2 twist

8

CNNO torsion

28

 

 

 

 

NO2 twist

9

CNNO torsion

28

 

 

 

 

NO2 twist

7

CNNO torsions

32

 

 

38(2)

44

Ring mode

10

CNCH torsions

39

 

 

41

60

NO2 wag

11

CNNO torsion

39

 

 

52(2)

63

NO2 wag

12

CNCH torsions

46

 

90

57

74

NO2 wag

13

CNNO torsion,

(CNC)-N wag

98

 

 

 

93

NO2 wag

14

, CNNO torsions

105

104

106

 

107

NO2 wag

15

CNNO torsions

137

 

 

 

 

NO2 wag and rock

16

CNNO torsions, NCH bends

177

 

 

178(2)

209

NO2 rock

17

CNNO torsion, CNN bends, CNH bends

221

208

205

249

229

NO2 rock and wag

18

CNNO torsions, CNCH torsions, CNN bends, CNH bends, CH bonds

241

223

224

257

 

NO2 wag

19

CNNO torsions, (CNC)-N wag, NCN bends, ONO bends, CH bonds

289

 

 

261(2)

 

Ring mode

20

CNNO torsions, CNN bends, NCH bends, CH bonds

294

 

 

 

290

Ring mode

21

CNCN torsions, CNN bends, CNC bends, CH bonds

319

345

347

316(2)

 

Ring mode

22

CNCN, NCN

381

 

 

343

325

Ring mode

23

CNCN, CNN, CNCH

401

410

414

 

371

 

 

 

 

 

 

424(2)

403

 

 

 

 

 

 

438(2)

406

NO2 sway

24

CNN, NNO

475

461

463

441

438

NO2 sway

25

NNO, CNCN

494

486

486

495

463

Ring mode

26

NNO, CNCN, CNN

512

 

 

 

 

Ring bending

27

NCN, NNO

538

 

 

 

 

NO2 scissors

29

ONO, CNCH

594

588

589

582

579

NO2 scissors

28

NCN, CNN,ONO

603

602

605

 

588

 

 

 

 

 

 

 

610

 

 

 

 

 

 

648(2)

651

NO2 scissors

30

ONO

690

670

669

 

676

CH2 wag

31

CNCH, NCN, NCH

708

 

 

 

 

CH2 wag

32

CNCH

713

738

739

741(2)

756

NO2 scissors

33

ONO

758

755

756

776(2)

761

NO2 scissors, CH2 rock

34

ONO

765

 

 

 

769

Ring mode

35

CNN

795

783

786

807

803

CH2 rock

36

CNN, NCN, CN

847

844

847

 

855

 

 

 

 

853

855

877

870

 

 

 

 

883

884

 

896

CH2 twist

37

NCH

914

915

920

 

909

CH2 twist

38

NCH

933

926

 

 

937

CH2 twist

39

NCN, NO, NN

939

947

943

957

951

CH2 twist

40

NCH

998

1019

1029

1027(2)

1011

CH2 rock

41

NCH

1015

 

 

 

1036

CH2 twist

42

NCH

1029

1040

 

1038(2)

 

CH2 twist

43

CNN

1061

 

 

1052

 

CH2 scissor

44

NCH, CN

1140