Page 61 - Nomenclature of Inorganic Chemistry (IUPAC Recommendations 2005)

S O L I D S IR-11.4

Examples:
3. (Li 2 ,Mg)Cl 2 denotes a s olid mixture intermediate in composition between LiCl and
MgCl 2 .
4. (Al 2 ,Mg 3 )Al 6 O 12 represents a s olid mixture intermediate in composition between
MgAl 2 O 4 ( ¼ Mg 3 Al 6 O 12 ) a nd Al 2 O 3 (spinel type) ( ¼ Al 2 Al 6 O 12 ).

In general, h owever, a notation in which there are variables which define composition s hould
be used. The ranges o f t he variables can also be indicated. Thus, a p hase involving
substitution of atom A f or B i s w ritten A mþx B n x C p (0 # x # n). The c ommas and
parentheses called f or above are not then required.

Examples:

5. Cu x Ni 1 x (0 # x # 1) is equivalent to (Cu,Ni).
6. KBr x Cl 1 x (0 # x # 1) is equivalent to K(Br,Cl).
7. Li 2 2x Mg x Cl 2 (0 # x # 1) is equivalent to (Li 2 ,Mg)Cl 2 but shows e xplicitly that
one vacant c ation position appears for every 2 Li replaced b y M g 2þ .
þ
8. Co 1 x O i ndicates that there are vacant cation sites; for x ¼ 0 t he formula
corresponds to the stoichiometric composition CoO.
9. Ca x Zr 1 x O 2 x indicates that Zr has been partly replaced by Ca, resulting in vacant
anion sites; for x ¼ 0 t he formula c orresponds to the stoichiometric composition
ZrO 2 .

If the variable x is limited this may be shown by using d or e instead o f x. A specific
composition or composition range can be indicated by stating the actual value of the variable
x (or d, o r e). This value c an be written in parentheses after the general formula. However,
the value o f t he variable may also be introduced in the formula i tself. This notation can be
used both for substitutional and for interstitial solid solutions. 6

Examples:

10. Fe 3x Li 4 x Ti 2(1 x) O 6 (x ¼ 0.35), or Fe 1.05 Li 3.65 Ti 1.30 O 6
11. LaNi 5 H x (05x56.7)

12. Al 4 Th 8 H 15.4
13. Ni 1 d O

¨
IR-11.4 P O I N T D E F E C T ( K R O G E R – V I N K ) N O T A T I O N
IR-11.4.1 General

As well as the chemical composition, information about point defects, site symmetry, and
site occupancy can be given by using additional symbols. T hese symbols may also b e u sed
to write quasi-chemical equilibria between point defects. 6

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