coordination number: meaning, definition, pronunciation and examples

Low (Academic/Specialised)
UK/kəʊˌɔː.dɪˈneɪ.ʃən ˌnʌm.bər/US/koʊˌɔːr.dɪˈneɪ.ʃən ˌnʌm.bɚ/

Technical, Scientific, Academic

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Quick answer

What does “coordination number” mean?

The number of atoms, ions, or molecules immediately surrounding a central atom in a crystal or a complex.

Audio

Pronunciation

Definition

Meaning and Definition

The number of atoms, ions, or molecules immediately surrounding a central atom in a crystal or a complex.

In a broader scientific context, it can refer to the number of nearest neighbours or direct contact points for a given entity within a defined structure. In logistics or management, it can sometimes refer to a count of coordination points or linkages.

Dialectal Variation

British vs American Usage

Differences

No significant differences in meaning or usage. Spelling follows the regional conventions for 'coordination' (UK often uses 'co-ordination', US uses 'coordination' without hyphen, though in science the hyphen is often dropped even in the UK).

Connotations

None beyond the strict scientific definition.

Frequency

Equally rare and specialised in both variants, confined to scientific literature.

Grammar

How to Use “coordination number” in a Sentence

The coordination number [of + ENTITY] is [NUMBER][ENTITY] has a coordination number of [NUMBER]

Vocabulary

Collocations

strong
high coordination numberlow coordination numbercoordination number ofaverage coordination number
medium
determine the coordination numbercalculate the coordination numbercoordination number increases
weak
metal coordination numberionic coordination numbercrystal coordination number

Examples

Examples of “coordination number” in a Sentence

verb

British English

  • N/A

American English

  • N/A

adverb

British English

  • N/A

American English

  • N/A

adjective

British English

  • The coordination-number analysis was crucial.

American English

  • Coordination-number calculations were performed.

Usage

Meaning in Context

Business

Not used.

Academic

Primary context. Used in chemistry, physics, and materials science lectures and papers to describe atomic/molecular structures.

Everyday

Virtually never used.

Technical

The definitive context. Used in research papers, technical manuals, and discussions on crystallography or inorganic chemistry.

Vocabulary

Synonyms of “coordination number”

Strong

ligancy

Neutral

ligancycoordination index

Weak

nearest neighbour count

Vocabulary

Antonyms of “coordination number”

N/A (quantitative term)

Watch out

Common Mistakes When Using “coordination number”

  • Using it to mean a telephone extension or a reference code.
  • Confusing it with 'oxidation number' or 'atomic number'.

FAQ

Frequently Asked Questions

No. Valency refers to the combining capacity of an atom (often based on electrons), while coordination number counts the immediate neighbours bonded to a central atom in a structure.

Yes, in complex or disordered structures, an average coordination number can be a non-integer value.

Rarely and only by analogy, for instance, to describe the number of ligands bound to a metal ion in an enzyme's active site.

In observed chemistry, it rarely exceeds 16. Theoretical models can suggest higher numbers under extreme conditions.

The number of atoms, ions, or molecules immediately surrounding a central atom in a crystal or a complex.

Coordination number is usually technical, scientific, academic in register.

Coordination number: in British English it is pronounced /kəʊˌɔː.dɪˈneɪ.ʃən ˌnʌm.bər/, and in American English it is pronounced /koʊˌɔːr.dɪˈneɪ.ʃən ˌnʌm.bɚ/. Tap the audio buttons above to hear it.

Phrases

Idioms & Phrases

  • N/A

Learning

Memory Aids

Mnemonic

Think of a central atom at a party. The 'coordination number' is the count of other atoms it's directly dancing with (bonded to).

Conceptual Metaphor

CENTRALITY AND CONNECTION (The central entity is defined by the number of its immediate connections).

Practice

Quiz

Fill in the gap
In a face-centred cubic lattice, each atom has a coordination of twelve.
Multiple Choice

In which field is the term 'coordination number' primarily used?