Table 2

Comparison of observed (Expt 1 = [45]; Expt 2 = [38]) and calculated IR frequencies for bulk α-FeOOH.

Mode
Calca
Calcb,c
Calcd
Expt 1
Expt 2

cm-1
(cm-1)
(cm-1)
(cm-1)
(cm-1)
(cm-1)

O-H
3416
3400
3227
3140
3200
O-H
3411
3391
3217


O-H
3404
3385
3213


O-H
3396
3373
3206


δ(OH)
954
974
1011

1000
δ(OH)
930
966
1007


δ(OH)
901
958
958


δ(OH)
896
911
956


γ(OH)
839
857
934
893
887
γ(OH)
810
848
896


γ(OH)
806
830
892


γ(OH)
797
819
888
793

Fe-Os
599
576
640
620
610
Fe-Os
547
567
623


Fe-Os
525
558
540


Fe-Os
482
547
538


δ(Fe-O-Fe)
467
477
526
495

δ(Fe-O-Fe)
424
461
481


δ(Fe-O-Fe)
417
453
459


δ(Fe-O-Fe)
395
441
442


Fe-Oas
391
426
410
405

Fe-Oas
376
413
405


Fe-Oas
371
397
401


Fe-Oas
357
413
399


O lattice
348
379
396


O lattice
345
372
395


O lattice
343
365
380


O lattice
321
361
375


Fe-O-Fe
309
354
360


Fe-O-Fe
293
338
334


Fe-O-Fe
284
328
307


Fe-O-Fe
268
314
301


Fe-O-Fe
258
309
293


Fe-O-Fe
254
301
288


Fe-O-Fe
242
287
270


Fe-O-Fe
228
274
266


Fe---Fe
223
262
255


Fe---Fe
211
246
241


Fe---Fe
179
243
237


Fe---Fe
174
240
206


FeO6 rock
143
230
185


FeO6
108
210
163


FeO6
78
177
132


FeO6
69
164
117


Tunnel Distortion
24
143
---



a = 1 × 1 × 1 unit cell; b = 1 × 3 × 2 supercell; c = average of 6 frequencies; d = 1 × 1 × 1 unit cell with SP-GGA+U.

Kubicki et al. Geochemical Transactions 2008 9:4   doi:10.1186/1467-4866-9-4