CuI

Copper(I) iodide · Cuprous iodide

Copper(I) iodide is a stable, semiconducting inorganic compound widely used as a catalyst and a precursor in chemical synthesis and electronics.

CuI
Crystal structure of CuI (cubic, F-43m (No. 216))
Ground-state structure · Materials Project
Overview

About Copper(I) iodide

Copper(I) iodide is a thermodynamically stable binary compound that functions as a semiconductor. Its robust structural nature is evidenced by its extensive representation across multiple crystallographic databases, reflecting its importance in materials science research. This material is widely utilized due to its predictable electronic behavior and chemical stability. It serves as a foundational component in various synthetic pathways and is increasingly relevant in the development of advanced electronic and optical technologies.

At a glance

Key Properties

Cross-validated computational properties for Copper(I) iodide, aggregated across 6 databases.

Band Gap

0.16–2.39 eV
Range across DFT structures · ground state: wide gap

Energy Above Hull

0.000 eV/atom
Best (lowest) across sources

Stability

Stable
4 DFT sources

Structures

121
6 databases, 17 space groups
Validation

Cross-Source DFT Agreement

How well independent DFT databases agree on the thermodynamics of CuI. Tight agreement means computed properties can be trusted without re-running calculations.

Agreement Score

0.94 / 1.00
Trust tier: high

Hull Spread

0.014 eV
EAH spread across sources

Sources Compared

3
jarvis, materials_project, oqmd

Space Group Consensus

Mixed (most: F-43m (No. 216))
Crystallography

Reported Structures

Lowest-energy structures reported for CuI, ranked by energy above hull.

Space GroupCrystal SystemBand Gap (eV)E above hull (eV/atom)E/atom (eV)Density (g/cm³)
P-3m1 (No. 164)trigonal1.650.0000-3.1555.73
F-43m (No. 216)cubic1.240.0000-0.153—
P3m1 (No. 156)trigonal1.460.0003-3.1555.74
F-43m (No. 216)cubic1.250.0012-0.151—
R3m (No. 160)trigonal1.250.0017-0.151—
P63mc (No. 186)hexagonal1.300.0046-0.148—
F-43m (No. 216)cubic1.180.0071-3.1485.81
P3m1 (No. 156)trigonal1.650.0072-0.145—
R3m (No. 160)trigonal1.160.0075-3.1485.81
P-3m1 (No. 164)trigonal1.650.0077-0.145—
Pc (No. 7)monoclinic1.150.0088-3.1465.67
P63mc (No. 186)hexagonal1.210.0089-3.1465.80
Uses

Applications

Where Copper(I) iodide is used.

Organic synthesis catalystOptoelectronic device fabricationCloud seedingPrecursor for copper-based materials
Intellectual Property

Patent Landscape

1 patent reference CuI or close compositional variants.

PatentTitleAssigneeGranted
9034354Bacteriostatic and anti-collagenolytic dental materials through the incorporation of polyacrylic acid modified——
Reference

Frequently Asked Questions

Common questions about Copper(I) iodide, answered from cross-validated data.

What is CuI?

Copper(I) iodide is a stable, semiconducting inorganic compound widely used as a catalyst and a precursor in chemical synthesis and electronics.

More questions
What is CuI used for?
Copper(I) iodide (CuI) is used in organic synthesis catalyst, optoelectronic device fabrication, cloud seeding, and precursor for copper-based materials.
What is the band gap of CuI?
Copper(I) iodide (CuI) has a DFT-computed band gap of 0.16–2.39 eV across 121 reported structures. Standard DFT underestimates band gaps, so the measured gap is typically larger.
Is CuI a metal, semiconductor, or insulator?
DFT predicts a band gap of up to 2.39 eV (a semiconductor). Measured gaps are typically larger.
Is CuI thermodynamically stable?
Yes — Copper(I) iodide (CuI) sits on the convex hull (energy above hull 0 eV/atom), i.e. stable.
What is the crystal structure of CuI?
The reference structure of Copper(I) iodide (CuI) is cubic symmetry, space group F-43m (No. 216).
How many polymorphs of CuI are known?
121 structures of CuI are reported across 6 databases, spanning 17 distinct space groups.
What elements does CuI contain?
Copper(I) iodide (CuI) contains Cu and I (2 elements).
Where does the data for CuI come from?
CuI data is cross-referenced from materials_project, jarvis, oqmd.
Comparison

How It Compares

As a highly stable and well-documented semiconductor, Copper(I) iodide serves as a standard reference material for cuprous halides. Its position on the convex hull ensures structural integrity, making it a reliable candidate for applications where consistent performance and long-term stability are essential requirements.

Data sources & attribution
  • materials_project — Data from the Materials Project (materialsproject.org). Cite: Jain et al., APL Materials 1, 011002 (2013). (CC-BY-4.0)
  • jarvis — Data from JARVIS (jarvis.nist.gov), NIST. Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020). (LicenseRef-US-Gov-PD)
  • oqmd — Data from the OQMD (oqmd.org). Cite: Saal et al., JOM 65, 1501 (2013); Kirklin et al., npj Comp. Mater. 1, 15010 (2015). (CC-BY-4.0)

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