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chemistry/tetrahedral-voids
View PricingTetrahedral Voids in an FCC Unit Cell
Locate tetrahedral voids in an FCC crystal, understand their geometry, and learn how they relate to real crystal structures like CaF2 and diamond.
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Key Concepts
Tetrahedral Coordination
A tetrahedral void is surrounded by 4 atoms at the corners of a tetrahedron, giving a coordination number of 4.
Position & Count in FCC
In an FCC unit cell there are 8 tetrahedral voids, located at fractional coordinates such as (1/4, 1/4, 1/4).
Crystal Examples
CaF2 (fluorite) fills all 8 tetrahedral voids; Sphalerite (ZnS) fills only half (4) in an alternating pattern.
Understanding Tetrahedral Voids
**Tetrahedral Voids** are the smallest interstitial sites in a crystal lattice, formed by four adjacent spheres positioned at the vertices of a regular tetrahedron.
In a **Face-Centered Cubic (FCC)** unit cell, there are exactly **eight tetrahedral voids**. Each void is located at the center of the eight sub-cubes (octants) that comprise the main unit cell volume.
Use our interactive visualizer to explore how these voids define critical structures like **Fluorite (CaF₂)**, **Sphalerite (ZnS)**, and the **Diamond** lattice, where varying degrees of void occupancy dictate the material's properties.
Frequently Asked Questions
Related Simulations
Octahedral Voids
An **Octahedral Void** is the interstitial space surrounded by six atoms in an octahedral arrangement. This resource visualizes the position and count of these voids within a **Face-Centered Cubic (FCC)** lattice.
Cubic Close Packing
**Cubic Close Packing (CCP)** is a high-efficiency crystal structure where atoms are arranged in an **A-B-C** stacking sequence. This resource visualizes the **Face-Centered Cubic (FCC)** unit cell and its 74.05% packing efficiency.
Hexagonal Close Packing
**Hexagonal Close Packing (HCP)** is a high-efficiency crystal structure with an **A-B-A-B** stacking sequence. This resource explores the **Hexagonal Unit Cell** and its 74.05% packing density.