HgO

mercury(II) oxide · mercuric oxide

Mercury(II) oxide is a stable, semiconducting inorganic compound historically utilized in battery production and chemical manufacturing.

HgO
Crystal structure of HgO (orthorhombic, Pnma (No. 62))
Ground-state structure · Materials Project
Overview

About mercury(II) oxide

Mercury(II) oxide is a thermodynamically stable inorganic compound that exists as a semiconducting material. Its structural versatility is highlighted by the extensive number of reported crystal structures, reflecting its significant role in historical and specialized chemical research.

This compound is primarily recognized for its historical utility in electrochemical systems and as a precursor in the synthesis of other mercury-containing materials. Its stability on the convex hull underscores its reliability as a fundamental building block in inorganic chemistry.

At a glance

Key Properties

Cross-validated computational properties for mercury(II) oxide, aggregated across 5 databases.

Band Gap

1.06–1.33 eV
Range across DFT structures · ground state: narrow gap

Energy Above Hull

0.000 eV/atom
Best (lowest) across sources

Stability

Stable
3 DFT sources

Structures

273
5 databases, 36 space groups
Validation

Cross-Source DFT Agreement

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

Agreement Score

1.00 / 1.00
Trust tier: high

Hull Spread

0.000 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 HgO, ranked by energy above hull.

Space GroupCrystal SystemBand Gap (eV)E above hull (eV/atom)E/atom (eV)Density (g/cm³)
Pnma (No. 62)orthorhombic1.210.0000-3.26410.77
——1.170.0000-0.460—
Pnma (No. 62)orthorhombic1.090.0000-0.245—
P21/m (No. 11)monoclinic1.210.0005-3.2639.88
P3221 (No. 154)trigonal1.270.0019-3.2629.97
P3121 (No. 152)trigonal1.330.0029-3.26110.79
——1.150.0059-0.454—
——1.080.0073-0.453—
——1.060.0120-0.448—
Pnma (No. 62)orthorhombic1.220.0197-0.225—
P3121 (No. 152)trigonal1.310.0209-0.224—
P3221 (No. 154)trigonal1.310.0210-0.224—
Uses

Applications

Where mercury(II) oxide is used.

mercury batterieschemical reagentpigment productioncatalysis
Reference

Frequently Asked Questions

Common questions about mercury(II) oxide, answered from cross-validated data.

What is HgO?

Mercury(II) oxide is a stable, semiconducting inorganic compound historically utilized in battery production and chemical manufacturing.

More questions
What is HgO used for?
mercury(II) oxide (HgO) is used in mercury batteries, chemical reagent, pigment production, and catalysis.
What is the band gap of HgO?
mercury(II) oxide (HgO) has a DFT-computed band gap of 1.06–1.33 eV across 273 reported structures. Standard DFT underestimates band gaps, so the measured gap is typically larger.
Is HgO a metal, semiconductor, or insulator?
DFT predicts a band gap of up to 1.33 eV (a semiconductor). Measured gaps are typically larger.
Is HgO thermodynamically stable?
Yes — mercury(II) oxide (HgO) sits on the convex hull (energy above hull 0 eV/atom), i.e. stable.
What is the crystal structure of HgO?
The reference structure of mercury(II) oxide (HgO) is orthorhombic symmetry, space group Pnma (No. 62).
What is the density of HgO?
The computed density of the ground-state structure of mercury(II) oxide (HgO) is 10.77 g/cm³.
How many polymorphs of HgO are known?
273 structures of HgO are reported across 5 databases, spanning 36 distinct space groups.
What elements does HgO contain?
mercury(II) oxide (HgO) contains Hg and O (2 elements).
Where does the data for HgO come from?
HgO data is cross-referenced from materials_project, oqmd, jarvis.
Comparison

How It Compares

As a standalone compound in this context, mercury(II) oxide serves as a primary reference point for mercury-based oxides, demonstrating high thermodynamic stability and distinct semiconducting behavior that distinguishes it from more reactive or less stable mercury-based species.

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)
  • 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)

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