We report the results of the first pseudopotential plane-wave simulations of the static properties of ammonia monohydrate phase I (AMH I) and ammonium hydroxide. Our calculated fourth-order logarithmic equation of state, at zero pressure and temperature, has molar volume, V0=36.38(3) cm3mol−1, bulk modulus, K0=9.59(9) GPa, and the first derivative of the bulk modulus with respect to pressure, K0=5.73(21). Both this and the lattice parameters are in very good agreement with experimental values. The monohydrate transforms, via a solid-state proton transfer reaction, to ammonium hydroxide (NH4OH) at 5.0(4) GPa. The equation of state of ammonium hydroxide is, V0=31.82(5) cm3mol−1,K0=14.78(62) GPa,K0=2.69(48). We calculate the reaction enthalpy, ΔH(NH4OH,s→NH3H2O,s)=−14.8(5) kJ mol−1 at absolute zero, and thus estimate the enthalpy of formation, ΔfH(NH4OH,s)=−356 kJ mol−1 at 298 K. This result places an upper limit of 84 kJ mol−1 on the barrier to rotation of the ammonium cation, and yields an average hydrogen bond enthalpy of ∼23 kJ mol−1.

1.
J. Loveday and R. J. Nelmes, in Science and Technology of High Pressure: Proceedings of AIRAPT-17, edited by M. H. Manghnani, W. J. Nellis, and M. T. Nicol (Universities Press, Hyderabad, India, 2000).
2.
D. A.
Johnson
,
J. Chem. Soc. Dalton Trans.
1988
,
445
(
1988
).
3.
R.
Prinn
and
B.
Fegley
,
Astrophys. J.
249
,
308
(
1981
).
4.
J. S.
Kargel
,
Icarus
100
,
556
(
1992
).
5.
J. I.
Lunine
,
Y. L.
Yung
, and
R. D.
Lorenz
,
Planet. Space Sci.
47
,
1291
(
1999
).
6.
S. K.
Croft
,
J. I.
Lunine
, and
J. S.
Kargel
,
Icarus
73
,
279
(
1988
).
7.
M. L.
Johnson
and
M.
Nicol
,
J. Geophys. Res., [Space Phys.]
92
,
6339
(
1987
).
8.
R. J. Nelmes, ISIS Experimental Report, RB 11246 (2000).
9.
A. D. Fortes, L. Vočadlo, J. P. Brodholt, and I. G. Wood (unpublished).
10.
A. D. Fortes, L. Vočadlo, J. P. Brodholt, and I. G. Wood (unpublished).
11.
R. J. Nelmes, ISIS Experimental Report, RB 9412 (1998).
12.
G.
Brink
and
L.
Glasser
,
J. Mol. Struct.
160
,
357
(
1987
).
13.
P.
Hohenberg
and
W.
Kohn
,
Phys. Rev. B
136
,
B864
(
1964
);
W.
Kohn
and
L. J.
Sham
,
Phys. Rev. B
140
,
A1133
(
1965
).
14.
J. P.
Perdew
and
Y.
Wang
,
Phys. Rev. B
45
,
13
(
1992
).
15.
D. R.
Hamann
,
Phys. Rev. B
55
,
10
157
(
1997
).
16.
S.
Tsuzuki
and
H. P.
Lüthi
,
J. Chem. Phys.
114
,
3949
(
2001
).
17.
D.
Vanderbilt
,
Phys. Rev. B
41
,
7892
(
1990
).
18.
G.
Kresse
and
J.
Furthmüller
,
Phys. Rev. B
54
,
11
(
1996
).
19.
H. J.
Monkhorst
and
J. D.
Pack
,
Phys. Rev. B
13
,
5188
(
1976
).
20.
W. S.
Benedict
,
J. Chem. Phys.
24
,
1139
(
1956
).
21.
J.
Demaison
,
L.
Margulès
, and
J. E.
Boggs
,
Chem. Phys.
260
,
65
(
2000
).
22.
S. B.
Andrews
,
N. A.
Burton
, and
I. H.
Hillier
,
Chem. Phys. Lett.
280
,
73
(
1997
).
23.
S.
Scheiner
and
M.
Čuma
,
J. Am. Chem. Soc.
118
,
1511
(
1996
).
24.
T.
Matsuo
,
A.
Inaba
,
O.
Yamamuro
, and
N.
Onada-Yamamuro
,
J. Phys.: Condens. Matter
12
,
8595
(
2000
).
25.
F.
Birch
,
J. Geophys. Res.
57
,
227
(
1952
).
26.
J.-P.
Poirier
and
A.
Tarantola
,
Phys. Earth Planet. Inter.
109
,
1
(
1998
).
27.
F. D.
Murnaghan
,
Proc. Natl. Acad. Sci. USA
30
,
244
(
1944
).
28.
J. H.
Rose
,
J. R.
Smith
,
F.
Guinea
, and
J.
Ferrante
,
Phys. Rev. B
29
,
2963
(
1984
).
29.
S. K.
Sikka
,
Phys. Rev. B
38
,
8463
(
1988
).
30.
J.
Hafner
,
Acta Mater.
48
,
71
(
2000
).
31.
S. K.
Croft
,
J. I.
Lunine
, and
J.
Kargel
,
Icarus
73
,
279
(
1988
).
32.
M.
Fuchs
,
M.
Bockstedte
,
E.
Pehlke
, and
M.
Scheffler
,
Phys. Rev. B
57
,
2134
(
1998
).
33.
H. D. B.
Jenkins
,
H. K.
Roobottom
,
J.
Passmore
, and
L.
Glasser
,
Inorg. Chem.
38
,
3609
(
1999
).
34.
L.
Mercury
,
P.
Vieillard
, and
Y.
Tardy
,
Appl. Geochem.
16
,
161
(
2001
).
35.
F.
Leclercq
,
P.
Damay
, and
M.
Foukani
,
J. Chem. Phys.
102
,
4400
(
1995
).
36.
J. E.
Bertie
and
M. R.
Shehata
,
J. Chem. Phys.
83
,
1449
(
1985
).
37.
J. M.
Besson
,
Ph.
Pruzan
,
S.
Klotz
et al.,
Phys. Rev. B
49
,
12
540
(
1994
).
38.
L.
Ojamäe
,
K.
Hermansson
,
R.
Dovesi
,
C.
Roetti
, and
V. R.
Saunders
,
J. Chem. Phys.
100
,
2128
(
1994
).
39.
P. A.
Giguere
,
Rev. Chim. Miner.
20
,
588
(
1983
).
40.
T.
Amano
,
J. Mol. Spectrosc.
103
,
436
(
1984
).
41.
R. J. C.
Brown
,
J. Mol. Struct.
345
,
77
(
1995
).
42.
A. C.
Lawson
,
R. B.
Roof
,
J. D.
Jorgensen
,
B.
Morosin
, and
J. E.
Schirber
,
Acta Crystallogr., Sect. B: Struct. Sci.
45
,
212
(
1989
).
43.
S. J.
van Reeuwijk
,
K. G.
van Beek
, and
D.
Feil
,
J. Phys. Chem. A
104
,
10
901
(
2000
).
44.
M. Kh. Karapet’yants and M. L. Karapet’yants, Thermodynamic Constants of Inorganic and Organic Compounds, translated by J. Schmorak (Humphrey Scientific Publishers, Ann Arbor, MI, 1970).
45.
D. A.
Johnson
,
Phys. Chem. Chem. Phys.
2
,
2903
(
2000
).
46.
D. L.
Hildenbrand
and
W. F.
Giaque
,
J. Am. Chem. Soc.
75
,
2811
(
1953
).
47.
A.
Alavi
,
R. M.
Lynden-Bell
, and
R. J. C.
Brown
,
J. Chem. Phys.
110
,
5861
(
1999
).
48.
CRC Handbook of Chemistry and Physics, 81st ed., edited by David R. Lide (CRC, Boca Raton, FL, 2001).
49.
H. D. B.
Jenkins
,
J. Solution Chem.
22
,
1029
(
1993
).
This content is only available via PDF.
You do not currently have access to this content.