Page 69 - Nomenclature of Inorganic Chemistry (IUPAC Recommendations 2005)

S O L I D S IR-11.9

forms or modifications, and in the past have been designated using a number of labelling
systems, including Greek letters and Roman numerals; the use of such non-systematic labels is
not acceptable. A r ational system based upon crystal structure should be used wherever
possible ( cf. S ections IR-3.4.4 and IR-4.2.5).
Polytypes and polytypoids can be regarded as a s pecial form of polymorphism and are
treated in more detail in Ref. 10.

IR-11.7.2 Use of crystal systems

Polymorphs are indicated by adding an italicized symbol denoting the crystal system after
the name o r f ormula. The symbols used are given in Table IR-3.1. For example, ZnS(c)
corresponds to the zinc blende structure or sphalerite, and ZnS(h) t o t he wurtzite structure.
Slightly distorted lattices m ay be indicated by using the circa sign ,. T hus, a s lightly
distorted cubic l attice would be expressed as (,c). In order to give more information, simple
well-known s tructures should be designated by giving the type compound in parentheses
whenever possible. For example, AuCd above 343 K s hould b e d esignated AuCd (CsCl type)
rather than AuCd(c).
Properties which strongly d epend on lattice and point symmetries may require the
addition o f t he space group to the crystal system abbreviation. For more d etails see Ref. 11.

IR-11.8 F I N A L R E M A R K S

ThisChapterdealswithsomebasicnotationandnomenclatureofsolid-statechemistry.Insome
areas, such as amorphous systems a nd glasses, t he nomenclature needs further develop-
ment. The reader is also referred to the work of the International Union of Crystallography.

IR-11.9 R E F E R E N C E S

1. Nomenclature of Inorganic Structure Types, J. Lima-de-Faria, E . H ellner, F. Liebau,
E. Makovicky and E. Parthe ´, Acta Crystallogr., Sect. A , 46, 1 –11 (1990).
2. M.L. McGlashan, Chemical Thermodynamics, A cademic Press, London, 1 979,
pp. 35–36.
3. Quantities, Units and Symbols in Physical Chemistry, S econd Edn., eds. I. Mills,
T. Cvitas, K. Homann, N . K allay and K. Kuchitsu, Blackwell Scientific Publications,
Oxford, 1993, p. 53. (The Green Book. The third edition is planned for publication in
2006.)
4. Compendium of Chemical Terminology, IUPAC R ecommendations, S econd Edn.,
eds. A.D. McNaught a nd A. Wilkinson, Blackwell Scientific Publications, Oxford,
1997. (The Gold Book.)
5. Chemical Nomenclature and Formulation of Compositions of Synthetic and Natural
Zeolites, R.M. Barrer, Pure Appl. Chem., 51, 1 091–1100 ( 1979).
6. F.A. Kro ¨ger and H.J. Vink, Solid State Phys., 3, 3 07–435 (1956).
7. W.B. P earson, A H andbook of Lattice S pacings and Structures of Metals a nd Alloys,
Vol. 2, Pergamon Press, O xford, 1967, p p. 1–2. For tabulated lattice parameters a nd

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