H4O5S

sulfuric acid monohydrate · H2SO4·H2O

H4O5S is a thermodynamically stable crystalline form of sulfuric acid monohydrate used in chemical research and industrial acid processing.

HOS
Crystal structure of H4O5S
Ground-state structure · Materials Project
Overview

About sulfuric acid monohydrate

H4O5S, commonly recognized as sulfuric acid monohydrate, is a thermodynamically stable crystalline phase formed by the hydration of sulfuric acid. As a wide-gap insulating material, it plays a significant role in understanding the phase behavior and structural chemistry of sulfur-based acids.

Its structural diversity is well-documented, with numerous reported configurations across major materials databases. This stability makes it a fundamental subject for researchers investigating the complex interactions within concentrated aqueous acid systems.

At a glance

Key Properties

Cross-validated computational properties for sulfuric acid monohydrate, aggregated across 4 databases.

Band Gap

5.26–6.50 eV
Range across DFT structures

Energy Above Hull

0.000 eV/atom
Best (lowest) across sources

Stability

On hull (stable)
2 DFT sources

Structures

13
4 databases, 5 space groups
Validation

Cross-Source DFT Agreement

How well independent DFT databases agree on the thermodynamics of H4O5S. Tight agreement means computed properties can be trusted without re-running calculations.

Agreement Score

1.00 / 1.00
Trust tier: medium

Hull Spread

0.000 eV
EAH spread across sources

Sources Compared

2
materials_project, nomad

Space Group Consensus

All match
Uses

Applications

Where sulfuric acid monohydrate is used.

Chemical synthesisAcid-base catalysis studiesIndustrial chemical processing
Reference

Frequently Asked Questions

Common questions about sulfuric acid monohydrate, answered from cross-validated data.

What is H4O5S?

H4O5S is a thermodynamically stable crystalline form of sulfuric acid monohydrate used in chemical research and industrial acid processing.

More questions
What is H4O5S used for?
sulfuric acid monohydrate (H4O5S) is used in chemical synthesis, acid-base catalysis studies, and industrial chemical processing.
What is the band gap of H4O5S?
sulfuric acid monohydrate (H4O5S) has a DFT-computed band gap of 5.26–6.50 eV across 13 reported structures.
Is H4O5S a metal, semiconductor, or insulator?
With a wide band gap up to 6.50 eV it is an insulator / wide-band-gap material.
Is H4O5S thermodynamically stable?
Yes — sulfuric acid monohydrate (H4O5S) sits on the convex hull (energy above hull 0 eV/atom), i.e. on hull (stable).
How many polymorphs of H4O5S are known?
13 structures of H4O5S are reported across 4 databases, spanning 5 distinct space groups.
What elements does H4O5S contain?
sulfuric acid monohydrate (H4O5S) contains H, O, and S (3 elements).
Where does the data for H4O5S come from?
H4O5S data is cross-referenced from latticegraph.
Comparison

How It Compares

As a distinct hydrate phase, H4O5S represents a critical point of stability within the broader landscape of sulfur-oxygen-hydrogen chemistry, serving as a benchmark for understanding how water molecules integrate into the acidic lattice structure.

Data sources & attribution
  • latticegraph — Lattice Graph Materials Intelligence Platform

Analyze H4O5S in the Lattice Graph platform

Polymorph comparison, confidence scoring, supply-chain risk, and patent monitoring — across 53 integrated data sources.

Explore the Platform →