Tl

thallium · element 81

Thallium is a soft, heavy, and thermodynamically stable metallic element known for its complex structural behavior and specialized industrial utility.

Tl
Crystal structure of Tl
Ground-state structure · Materials Project
Overview

About thallium

Thallium is a soft, heavy post-transition metal that exists as a thermodynamically stable phase. Its metallic character and structural versatility are evidenced by the numerous crystalline forms documented across scientific databases, reflecting its complex behavior in the solid state.

As a distinct elemental material, thallium is valued for its specific physical properties, though its use is strictly regulated due to its toxicity. It remains a subject of fundamental interest in materials science for its role in developing advanced optical components and specialized alloys.

At a glance

Key Properties

Cross-validated computational properties for thallium, aggregated across 4 databases.

Band Gap

Metallic / not reported

Energy Above Hull

0.000 eV/atom
Best (lowest) across sources

Stability

On hull (stable)
2 DFT sources

Structures

45
4 databases, 8 space groups
Validation

Cross-Source DFT Agreement

How well independent DFT databases agree on the thermodynamics of Tl. 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
jarvis, materials_project

Space Group Consensus

All match
Synthesis

Synthesis Routes

Literature-extracted synthesis procedures targeting Tl.

Sol Gel
Procedure available · ceder_sol_gel
Sol Gel
Procedure available · ceder_sol_gel
Sol Gel
Procedure available · ceder_sol_gel
Sol Gel
Procedure available · ceder_sol_gel
Sol Gel
Procedure available · ceder_sol_gel
Sol Gel
Procedure available · ceder_sol_gel
Uses

Applications

Where thallium is used.

optical glass manufacturingsemiconductor researchspecialized alloysradiation detection equipment
Reference

Frequently Asked Questions

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

What is Tl?

Thallium is a soft, heavy, and thermodynamically stable metallic element known for its complex structural behavior and specialized industrial utility.

More questions
What is Tl used for?
thallium (Tl) is used in optical glass manufacturing, semiconductor research, specialized alloys, and radiation detection equipment.
What is the band gap of Tl?
thallium (Tl) is computed to be metallic (no band gap) in the reported DFT structures.
Is Tl a metal, semiconductor, or insulator?
Computed band structures report no gap, so it is metallic.
Is Tl thermodynamically stable?
Yes — thallium (Tl) sits on the convex hull (energy above hull 0 eV/atom), i.e. on hull (stable).
How many polymorphs of Tl are known?
45 structures of Tl are reported across 4 databases, spanning 8 distinct space groups.
How is Tl synthesized?
Literature-reported routes for Tl include sol gel, solid state (10 procedures documented).
What elements does Tl contain?
thallium (Tl) contains Tl (1 element).
Where does the data for Tl come from?
Tl data is cross-referenced from latticegraph.
Comparison

How It Compares

As a pure elemental metal, thallium occupies a unique position in materials science, serving as a foundational reference point for heavy metal chemistry rather than acting as a member of a broader compound class.

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

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