Tentatively assignation

Z-N

FTIR bands

Z-H+

FTIR bands

Z-NH4+

FTIR bands

Z-250

FTIR bands

Z-500

FTIR bands

ν OH

3424

3436

3458

3469

3462

ν N-H

3230

3240

3242

δ H2O

1632

1633

1632

1639

1635

δ NO3

1384

1383

δ NH4

1401

(a) νaT-O-T

1206

1206

1207

1200

1158

(b)νaT-O-T

1053

1080

1053

1061

1062

νsSi-OH

955

(a)νsT-O-T

787

794

793

786

789

(b)νsT-O-T

607

608

608

606

609

Network modes: “ring elongation”

453

463

452

454

458