## What makes an element tetrahedral?

A tetrahedral is an object that has a central atom surrounded by four other atoms. The central atom bonds with each of the surrounding atoms, which form bond angles of 109.5°.

**What is tetrahedron meshing?**

Tetrahedron. A tetrahedron has 4 vertices, 6 edges, and is bounded by 4 triangular faces. In most cases a tetrahedral volume mesh can be generated automatically.

**What is free tetrahedral Comsol?**

Free Tetrahedral. Add a Free Tetrahedral node ( ) to create an unstructured tetrahedral mesh. If no selection is specified, this feature creates a mesh on the remaining domains, boundaries, edges and points. You can control the number, size, and distribution of elements by using Size and Distribution subnodes.

### Why do we use tetrahedral mesh?

Tetrahedral elements can fit better complex geometry. However, when you integrate the shape functions with points of Gauss it is less accurate than hexahedral elements. The reason for this lays on the mapping from real to natural space of integration.

**How do you know if you are a tetrahedral?**

If your metal ion is in group 8 or has a d8 configuration, look at the crystal field splitting diagram. Square planar complexes have a four tiered diagram (i.e. four different sets of orbitals with different energies). If it has a two tiered crystal field splitting diagram then it is tetrahedral.

**How do you know if something is tetrahedral geometry?**

In a tetrahedral molecular geometry, a central atom is located at the center with four substituents that are located at the corners of a tetrahedron. The bond angles are cos−1(−1⁄3) = 109.4712206… ° ≈ 109.5° when all four substituents are the same, as in methane (CH 4) as well as its heavier analogues.

#### What is the difference between tetrahedral and hexahedral mesh?

Tetrahedral elements can fit better complex geometry. However, when you integrate the shape functions with points of Gauss it is less accurate than hexahedral elements. If it is not possible (curved geometries, accute angles or similar) then go with tetrahedal but controlling the distortion of the elements.

**What is curvature factor in Comsol?**

Curvature factor — limits how big a mesh element can be along a curved boundary (lower value => finer mesh) Resolution of narrow regions — controls the number of layers of mesh elements in narrow regions (higher value => finer mesh)

**How do I know my mesh size Comsol?**

One way to quickly get an overview of the created mesh is to have a look at the statistics in the Mesh Statistics window, which we open by right-clicking the Mesh head node. The Mesh Statistics window, showing a wide variety of statistics for different selections and quality measures.