K4I2O

K4I2O is a thermodynamically stable, semiconducting inorganic compound containing potassium, iodine, and oxygen.

IKO
Crystal structure of K4I2O (tetragonal, I4/mmm (No. 139))
Ground-state structure · Materials Project
Overview

About K4I2O

K4I2O is a complex inorganic compound composed of potassium, iodine, and oxygen. As a thermodynamically stable phase residing on the convex hull, it represents a well-defined structural arrangement that is significant for understanding the interplay between alkali metals and halides in oxide lattices.

This material exhibits semiconducting electronic character, making it an interesting subject for fundamental studies in solid-state chemistry. Its existence across multiple reported structures highlights its potential for diverse atomic configurations, which are critical for researchers investigating novel electronic materials.

At a glance

Key Properties

Cross-validated computational properties for K4I2O, aggregated across 3 databases.

Band Gap

1.39–1.51 eV
Range across DFT structures · ground state: wide gap

Energy Above Hull

0.000 eV/atom
Best (lowest) across sources

Stability

Stable
3 DFT sources

Structures

5
3 databases, 1 space group
Validation

Cross-Source DFT Agreement

How well independent DFT databases agree on the thermodynamics of K4I2O. Tight agreement means computed properties can be trusted without re-running calculations.

Agreement Score

0.74 / 1.00
Trust tier: medium

Hull Spread

0.066 eV
EAH spread across sources

Sources Compared

3
jarvis, materials_project, oqmd

Space Group Consensus

All match
Crystallography

Reported Structures

Lowest-energy structures reported for K4I2O, ranked by energy above hull.

Space GroupCrystal SystemBand Gap (eV)E above hull (eV/atom)E/atom (eV)Density (g/cm³)
——1.510.0000-1.447—
I4/mmm (No. 139)tetragonal1.390.0000-1.482—
I4/mmm (No. 139)tetragonal1.250.0662-3.2062.90
I4/mmm (No. 139)tetragonal———2.88
I4/mmm (No. 139)tetragonal———2.79
I4/mmm (No. 139)tetragonal———2.85
Uses

Applications

Where K4I2O is used.

Solid-state chemistry researchFundamental materials science studies
Reference

Frequently Asked Questions

Common questions about K4I2O, answered from cross-validated data.

What is K4I2O?

K4I2O is a thermodynamically stable, semiconducting inorganic compound containing potassium, iodine, and oxygen.

More questions
What is K4I2O used for?
K4I2O is used in solid-state chemistry research and fundamental materials science studies.
What is the band gap of K4I2O?
K4I2O has a DFT-computed band gap of 1.39–1.51 eV across 5 reported structures. Standard DFT underestimates band gaps, so the measured gap is typically larger.
Is K4I2O a metal, semiconductor, or insulator?
DFT predicts a band gap of up to 1.51 eV (a semiconductor). Measured gaps are typically larger.
Is K4I2O thermodynamically stable?
Yes — K4I2O sits on the convex hull (energy above hull 0 eV/atom), i.e. stable.
What is the crystal structure of K4I2O?
The reference structure of K4I2O is tetragonal symmetry, space group I4/mmm (No. 139).
How many polymorphs of K4I2O are known?
5 structures of K4I2O are reported across 3 databases, spanning 1 distinct space group.
What elements does K4I2O contain?
K4I2O contains I, K, and O (3 elements).
Where does the data for K4I2O come from?
K4I2O data is cross-referenced from oqmd, jarvis, materials_project, mpaloe.
Comparison

How It Compares

As a distinct inorganic compound, K4I2O serves as a specialized reference point in the study of complex potassium-based oxides, offering a unique structural profile that distinguishes it from simpler binary or ternary oxides.

Data sources & attribution
  • 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)
  • jarvis — Data from JARVIS (jarvis.nist.gov), NIST. Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020). (LicenseRef-US-Gov-PD)
  • materials_project — Data from the Materials Project (materialsproject.org). Cite: Jain et al., APL Materials 1, 011002 (2013). (CC-BY-4.0)
  • mpaloe — Data from MP-ALOE. Cite: Kuner et al., npj Comput. Mater. (2025), doi:10.1038/s41524-025-01834-9.

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