Search Chemistry Quick Search mode
Chemistry searches can be performed either via the “Quick Search” (Fig. 1) or the “Visual Search” (Fig. 2) screen.
Figure 1: Chemistry “Quick Search” screen.
Figure 2: Chemistry “Visual Search” screen.
In “Quick Search” mode it is possible to search for
- Composition
- Structural Formula
- Number of Elements
- Number of Formula Units
- Chemical Name
- Mineral Name
- Mineral Group
- ANX Formula
- AB Formula
The search in “Composition” is not case-sensitive. Enter all elements/group of elements that should appear in the desired compound; search field entries have to be separated by a blank; they are combined by logical AND. The Number of Elements can be entered as well – this is especially useful when search terms include groups. The following search terms are allowed:
- Chemical elements, note: D for Deuterium and T for Tritium is allowed,
- Groups (in the meaning of “Groups in the Periodic Table of Elements”) of elements (see Tab. 1 for nomenclature),
- Periods of elements (see Tab. 2 for nomenclature) and
- Groups, such as metals, transition metals and non-metals (see Tab. 3 for nomenclature, Fig. 3 for information which elements belong to metals and non-metals).
Search terms are combined by logical AND; it is possible to modify the combination in the following ways:
- In order to combine certain elements/element groups by OR, place them in parentheses: (Na K) will search for entries containing Na OR K.
- In order to exclude certain elements/element groups (NOT), place a hyphen (“-“) in front of the entry: -K will search for entries NOT containing K.
Examples:
Composition | # of elements | Result |
(Na K) Br | 2 | NaBr or KBr |
-Na -K Br | 2 | all bromides except NaBr and KBr |
-Na -K LIG FG | 2 | all alkali metal halogenides except NaX and KX; will include e.g. CsBr3 and Cs2I8 |
Additionally, searches can be performed by specifying the stoichiometric coefficients (Co. min/max) and/or the oxidation numbers (Ox. min/max) of elements (EL). The colon is used as a separator:
EL:Co.(min):Co.(max):Ox.(min):Ox.(max)
Examples:
Composition | # of elements | Result |
-Na -K LIG:1:1 FG:1:1 | 2 | all alkali metal halogenides except NaX and KX; will not include e.g. CsBr3 and Cs2I8 |
Cr:::4:4 | 2 | all compounds with an oxidation number of +4 for Cr, such as CrO2 or Cr3B4 |
Cr:1:1:4:4 | 2 | all compounds with an oxidation number of +4 for Cr, such as CrO2, but not Cr3B4 |
Table 1: ICSD names for Periodic Table groups
Chemical Group | ICSD name | Conventional name(s) | |
1 | LIG | Alkali metals, group I A, 1st main group | |
2 | BEG | Alkaline earth metals, group II A, 2nd main group | |
3 | SCG | Scandium group, group III B | |
4 | TIG | Titanium group, group IV B | |
5 | VG | Vanadium group, group V B | |
6 | CRG | Chrome group, group VI B | |
7 | MNG | Manganese group, group VII B | |
8 | FEG | Iron group | group VIII B |
9 | COG | Cobalt group | |
10 | NIG | Nickel group | |
11 | CUG | Copper group, group I B | |
12 | ZNG | Zinc group, group II B | |
13 | BG | Boron group, group III A, 3rd main group | |
14 | CG | Carbon group, group IV A, 4th main group | |
15 | NG | Nitrogen group, group V A (Pnictogens), 5th main group | |
16 | OG | Oxygen group, group VI A (Chalkogens), 6th main group | |
17 | FG | Fluorine group, group VII A (Halogens), 7th main group | |
18 | HEG | Noble gases, group VIII A | |
Table 2: ICSD names for Periods
Chemical Period | ICSD name |
1 | 1PE |
2 | 2PE |
3 | 3PE |
4 | 4PE |
5 | 5PE |
6 | 6PE |
7 | 7PE |
Table 3: ICSD names for other chemical groups of elements
Group | ICSD name |
Metals | MET |
Transition metals (does not include f-block elements!) | TME |
Non-metals | NME |
Lanthanoids (incl. La) | LAN |
Actinoids (incl. Ac) | ACT |
Figure 3: Border (red line) between metals (“MET”, blue fields) and non-metals (“NME”, grey fields) in ICSD
Examples:
Composition | # of Elements | Structured Formula | Result |
Na Cl | 2 | NaCl | |
Na Cl | 3 | e.g. NaClO3, NaClO2, NaMnCl3, NaAlCl4, Na2ZnCl4 | |
Na Cl O | 3 | (Cl O3) | NaClO3 |
Cl O | 3 | (Cl O3) | e.g. NaClO3, KClO3, RbClO3, Pb(ClO3)2, Hg2(ClO3)2 |
TME Cl O | 3 | (Cl O3) | Hg2(ClO3)2, but not e.g. NaClO3, Pb(ClO3)2 etc. |
BEG Cl O | 3 | (Cl O3) | Ba(ClO3)2, Sr(ClO3)2, but not e.g. NaClO3, Pb(ClO3)2, Hg2(ClO3)2 etc. |
LIG FG O | 3 | e.g. RbIO3, NaBrO3, NaClO4, Rb3IO5, Cs2I4O11 | |
LIG FG 5PE | 3 | e.g. K2PtI5, Na3Sb5F18 |
Chemical name
The search term is not case-sensitive. You can enter the common chemical name for desired compounds.
Examples:
Chemical name | Result |
sulfate | e.g. Na2SO4, Na2SO4∙10H2O, NaHSO4, Na2S2O3, NaMg2Fe5(SO4)7(OH)6(H2O)33 |
phosphate | e.g. Na4(P2O7)(H2O)10, Na(PF6)(H2O) |
ammonium osmate | e.g. ((CH3)4N)2(Os(NO)FI4), (((C4H9)4N)3(Se8(Re5OsCl6)))((C2H5)2O)2 |
Mineral name/Mineral group
The search term is not case-sensitive. You can enter the common mineral name or mineral group for desired compounds.
Examples:
Mineral name | Mineral group | Result |
Bloedite | Na2Mg(SO4)2(H2O)4 | |
Feldspar | Na(AlSi3O8), K(AlSi3O8) | |
Feldspar | BaNa2(Al4Si4O16), CaB2Si2O8 | |
Stishovite | SiO2 |
The ANX formula is generated according to the following rules:
- H is not taken into account, even if coordinates are available.
- The coordinates for all sites of all other atoms must be determined.
- Different atom types on the same position are being treated as one single atom type. The relevant atom type is the one with the highest site occupation factor. If the SOFs are equal, the first atom type is the relevant atom type.
Exception to this rule: if anions and cations occupy the same site they will not be treated as one atom type. - All sites occupied by the same atom type are combined unless the oxidation state is different:
Fe2+(Fe3+)2O4 → AB2X4
(Fe2.6667+)3O4 → A3X4 - For each atom type the multiplicities are multiplied by the SOFs and the products are added. The sums are rounded and divided by the greatest common divisor. If the rounded sum is equal to zero all sums are being multiplied by a common factor so that the smallest sum is equal to 1.0, so no element will be omitted.
- Cations are assigned the symbols A–M, neutral atoms N–R and anions are assigned X, Y, Z, S–W.
- The symbols are being sorted alphabetically and the characters are assigned according to ascending indices: AB2X4, not A2BX4.
- All ANX formulae with more than 4 cation symbols, 3 neutral symbols or 3 anion symbols are deleted. This measure limits the number of different ANX formulae.
Examples:
Chemical formula | ANX formula |
Mg3Al2(SiO4)3 | A2B3C3X12 |
Ca3(Al1.3325Fe0.6675)Si3O12 | A2B3C3X12 |
(Mg2.7Fe0.3)(Al1.7Cr0.3)Si3O12 | A2B3C3X12 |
Al4H2(SO4)7(H2O)24 | A4B7X52 |
H2O | X |
AB Formula
In general, the same rules for generating the AB formula apply as for the ANX formula. In contrast to the ANX formula, H is taken into account and there are no predefined letters for cations, anions or neutral atom types.
Examples:
Chemical formula | AB formula |
Li2SO4 | AB2C4 |
H2O | AB2 |
K2(O2(SO3)2) | ABC4 |
K2(S2O7) | A2B2C7 |
Na6O(SO4)2 | A2B6C9 |
Visual Search
The Visual Search interface allows easy entering of search terms (Fig. 4): by clicking on an element symbol additional entry fields will show up (Fig. 4 (3.)), where the following modifications can be applied:
- the logical combination can be selected (AND/NOT),
- in the element symbol field more than one entry is possible; all entered symbols will be combined by logical OR,
- the range for stoichiometric coefficients (Co.(min)/Co.(max)) can be entered,
- the range for oxidation numbers (Ox.(min)/Ox.(max)) can be enterd.
You can specify the maximum number of elements (Fig. 4 (1.)) and the units of coefficients (Fig. 4 (2.)):
- moles,
- atom percent,
- mass percent
by selecting the appropriate entry from the dropdown box.
Checking the box “Restrict total number of elements to selected number of elements” (Fig. 4 (4.)) will automatically limit the number of elements to the number of the selected ones.
