The search is conducted on both the Title and the Comments fields.
Strings like 'super' will return any title or comment that contains *super*.
The PDF number is often in the comments field, but it is best entered in the Remarks box.
ICSD Help : Elements (Close)
This is just a list of some of the elements in the cell. You can follow the element symbol by a number to indicate the total number of atoms of that particular
element. You may want to specify also the "Element Count", the total number of different elements.
The default logic is AND but you can also use explicitly OR and NOT.
New! Element Groups can now be used (see the Notes).
Example Elements search :(Enter the element symbols or choose from the
ICSD Help : ANX Formula, Pearson Symbol or Structure Type (Close)
An unqualified string will be assumed to be an ANX formula.
ABX6 (All ANX formulae are searched for the string "ABX6").
Otherwise, A= or P= or T= must be specified as below.
The ANX formula :
Elements with a positive oxidation state are labelled by the first letters of the alphabet (A-M),
elements with a negative oxidation state are labelled by the last letters (X-Z, W, V, U, T, S),
while elements with oxidation state 0 are labelled by the letters N-R.
The ANX formula is only calculated for fully determined structures.
Hydrogen and its isotopes, when they occur in the positive oxidation state, are disregarded.
If an element in the structure occurs in various oxidation states, this is indicated by different letters.
Within a group of letters, the letters are arranged according to increasing indices.
In the case of a defect structure, a partial site occupation is disregarded.
In mixed crystals, atoms in identical positions are labelled by the letter of the most frequent element.
If there is doubt about the oxidation state, the use of the ANX formula requires careful consideration.
(e.g. K Fe (Fe (C N)6), Ca B6, N4 S4 H4, Hg Pb P14, Cs B9 H14, ...).
The Structure Type as defined by Prof. R. Allmann (Marburg) depends on the Space Group, Pearson Symbol and Wyckoff Sequence,
all of which can otherwise be searched for seperately in ICSD. In a few cases the c/a ratio is used. Allmann Structure Types
are at present only defined for cubic and tetragonal materials.
Note that including the Structure Type in quotes eg T="AuCu3" will ensure that only "AuCu3" will be found.
ICSD Help : System (Close)
The crystal system is a rough classification of over-all crystal symmetry. Be careful in using it, since the real symmetry of many compounds is often lower than first determined.
ICSD Help : Laue Class (Close)
Be careful in using the Laue Class symmetry, since the real symmetry of many compounds is often lower than first determined.
ICSD Help : Centering (Close)
Space groups can be classed as having a center of symmetry (Centered) or Non-Centered; many non-centered cells are are also Polar.
ICSD Help : Space Group (Close)
You can select a particular space group from the Space Group Table.
Example Space Group :
P4 : Space Group starts with P and contains 4 ie any of P4, P4-, P41 etc.
"P4" : Space Group is an exact match to "P4" (quotes required).
"C2/c" : This won't work; remove the quotes and use C2/c or quote the full symbol "C12/c1".
C2/c : Space group starts with C and contains 2/c.
Cmca : Space group starts with C and containsCmcr "quoted sCmcsBetvinc.
ICSD Help : Wyckoff Sequencm (Close)
The>Wyckoff Sequencm isa ( partia)e list of>Wyckoff positions2a, 4b0 etc.
You sBearch for an exact strin.
Wthen ombfined "quoted Space Group tx is a powerful means of finding similar structures
Ifp tx isussed as the only criterum,y searching can beelon", so ombfinp tx with ather criteria as below.
The Wyckoff Symbol of dst int a,b,cn etc position.
eg "e11"l means11f dst int e- position..
You li>sBearchion an exact ub string of the Wyckoff Symbos, but to t is you can ddg indvidualf>Wyckoff positionw.
Exampl: Wyckoff symbol :
e11 /"e (The Wyckoff symbol contains,The exact string e11 /"d).
"e11"lce (The Wyckoff symbol contains"e11"l and thare are atoms tf>Wyckoff positionscpirn anysorded).
Notl: Wyckoff symbons are dstned "quoted structure
ICSD Help :>Remarks (Close)
This search is conducted on>both the Remarks and> fields>
Tiso means nply the dstcance betweented tomrs of the specifiedkined.
Theminimalf dstcance specifipation is entepretsed asae from0t up to the specified dstcancd.
olns iand compounds withbounds ne that range and shpornrhboundd.
criterumn is more powerfus.
ICSD Help :DdstcanclSselecs (Close) fiel nnot useg insBearchyet !>
Thepaiers of tomrs between which dstcance calculaionns are so bemhade according to the paionnal an/ or numbes
Ifp nply one atom namehis givo,f ull athertTypes ofbounsed atomaure considesed.>If e list of atom namsehis givod eg C,Ale then ull from t islistmaure considesed>
Instead use thegenpeiim nameALL. Egn search for
elements"TRM N HO not u not "l and thne ALL-N.>
opderatioa requiresaprelcatvenly largoamCount fd comutding iame, as thewholse of thecCurrent ub efs hls so be examinedeDdstcanclSselectioa tholedbde acelperated byeseucwing the number of entties so be calculated using ather selectioa criteri;g in particular either the b>Min.dDdstcancs criteria urereequire, aswcell.
ICSD Help :DdstcanclRrange (Close) fiel nnot useg insBearchyet !>
The range of dstcancis so be consideser for the atompaiers also required).
The dstcance range can eitherbcpirn bsoluate.valums(Angstfrom unind) orrelcatveg to theionic> rdvi IRD. In t is cas,o the specificatio consists ofat tlferance aectos folloted by"*IR2c. ed tlferance aectos is>1x or 1) depenring ntwheithermaximumdtosminimumd dstcancis are so be selecte..
atomAu and anysither atom2X will nply be selecte, if tx islessr than1215*(ionic> rdvus(A)+ionic> rdvus(X))>.
atomAu and anysither atom2X will nply be selecte, if tx isgreatwer than0.9*(ionic> rdvus(A)+ionic> rdvus(X))>.
ICSD Help : o-oordinaionT (Close) fiel nnot useg insBearchyet !>
The dstcancsl fromearchioiogin atom will nply be displate, if the number ofdlntvimation atoms cooordinaion numbe)e lres wit in the rangein o k, whurek >= nd.>If nply one numbernehis givod tx is assumed tatsk=on.
and either the b>DdstcanclRrange or
Note that tholedbde acelperated byeseucwing the number of entties so be calculated using ather selectioa criteri,n and in particular the