SiI2

SiI2 is a metastable semiconducting compound composed of silicon and iodine that is studied for its structural properties in the context of silicon-based materials.

Crystal structure of SiI2 (monoclinic, P21/c (No. 14))
Ground-state structure · Materials Project
Overview

About SiI2

SiI2 is a metastable silicon-iodide compound that functions within the broader landscape of silicon-based materials. As a semiconducting species, it represents a unique structural configuration that researchers study to understand phase stability and potential electrochemical pathways in energy storage systems.

Its significance lies in the diverse structural possibilities inherent to silicon-iodide chemistry. By investigating this compound, scientists gain insights into the fundamental behavior of silicon-based anodes, contributing to the development of more robust materials for next-generation battery architectures.

At a glance

Key Properties

Cross-validated computational properties for SiI2, aggregated across 4 databases.

Band Gap

2.39 eV
Range across DFT structures

Energy Above Hull

0.026 eV/atom
Best (lowest) across sources

Stability

Metastable
2 DFT sources

Structures

43
4 databases, 11 space groups
Crystallography

Reported Structures

Lowest-energy structures reported for SiI2, ranked by energy above hull.

Space GroupCrystal SystemBand Gap (eV)E above hull (eV/atom)E/atom (eV)Density (g/cm³)
P21/c (No. 14)monoclinic2.390.0259-3.3823.16
P1 (No. 1)Triclinic5.16
Pm (No. 6)Monoclinic4.41
C2/c (No. 15)Monoclinic3.17
C2/c (No. 15)Monoclinic3.87
P1 (No. 1)Triclinic5.51
P1 (No. 1)Triclinic3.20
C2/m (No. 12)Monoclinic6.58
P-1 (No. 2)Triclinic8.99
C2/m (No. 12)Monoclinic3.58
P-1 (No. 2)Triclinic9.04
P-1 (No. 2)Triclinic3.72
Uses

Applications

Where SiI2 is used.

Silicon anode researchMaterials science studiesSolid-state chemistry research
Reference

Frequently Asked Questions

Common questions about SiI2, answered from cross-validated data.

What is SiI2?

SiI2 is a metastable semiconducting compound composed of silicon and iodine that is studied for its structural properties in the context of silicon-based materials.

More questions
What is SiI2 used for?
SiI2 is used in silicon anode research, materials science studies, and solid-state chemistry research.
What is the band gap of SiI2?
SiI2 has a DFT-computed band gap of 2.39 eV across 43 reported structures.
Is SiI2 a metal, semiconductor, or insulator?
With a band gap up to 2.39 eV it is a semiconductor.
Is SiI2 thermodynamically stable?
SiI2 has a lowest energy above hull of 0.026 eV/atom (metastable).
What is the crystal structure of SiI2?
The lowest-energy reported polymorph of SiI2 is monoclinic symmetry, space group P21/c (No. 14).
What is the density of SiI2?
The computed density of the ground-state structure of SiI2 is 3.16 g/cm³.
How many polymorphs of SiI2 are known?
43 structures of SiI2 are reported across 4 databases, spanning 11 distinct space groups.
What elements does SiI2 contain?
SiI2 contains I and Si (2 elements).
Where does the data for SiI2 come from?
SiI2 data is cross-referenced from materials_project, mpaloe, jarvis.
Comparison

How It Compares

Within the silicon anode materials class.

Unlike the highly stable and widely utilized elemental silicon or the robust silicides like MoSi2 and Mg2Si, SiI2 exists in a metastable state. While compounds such as BaSi2 are frequently explored for their specific optoelectronic properties, SiI2 is primarily examined for its structural complexity and the role of iodine in modifying the silicon framework compared to more conventional metal silicides.

Explore

Related Compounds

Other Silicon Anode Materials in the database.

Data sources & attribution
  • materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
  • mpaloe — Data from mpaloe.
  • jarvis — Data from JARVIS (NIST). Cite: Choudhary et al., npj Comp. Mater. 6, 173 (2020).

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