Table of Contents

## What is the lattice constant for BCC?

BCC has 2 atoms per unit cell, lattice constant a = 4R/√3, Coordination number CN = 8, and Atomic Packing Factor APF = 68%.

**What is the value of lattice constant?**

The lattice constant for the photonic crystal must be comparable to the wavelength of light, typically in the range of 0.5 to 2 μm.

**What is lattice and lattice constant?**

A lattice constant or lattice parameter is one of the physical dimensions and angles that determine the geometry of the unit cells in a crystal lattice.

### What is the lattice constant for FCC crystal?

= 2R√2

FCC has 4 atoms per unit cell, lattice constant a = 2R√2, Coordination Number CN = 12, and Atomic Packing Factor APF = 74%.

**How do you find the BCC structure?**

In the bcc structure each atom has c1=8 c 1 = 8 nearest neighbours (coordination number) at a distance of dc1=2r=√32a≈0.866a(3) (3) d c 1 = 2 r = 3 2 a ≈ 0.866 a and c2=6 c 2 = 6 next-nearest neighbours at a distance of dc2=a≈2.3r≈1.15dc1.

**How many lattice points are there in BCC?**

Therefore, the bcc lattice can be considered as a unit cubic cell with two lattice points per cell. The number of nearest neighbors of each lattice point is 8. Alternately, one can state that the coordination number is 8.

## How do you calculate BCC volume?

Solution:

- We are going to use the Pythagorean Theorem to determine the edge length of the unit cell. That edge length will give us the volume.
- We will use the average mass of one V atom and the two atoms in bcc to determine the mass of V inside the unit cell.
- Step 2 divided by step 1 gives the density.

**Is aluminum FCC or BCC?**

Table 1: Crystal Structure for some Metals (at room temperature)

Aluminum | FCC | FCC |
---|---|---|

Cadmium | HCP | BCC |

Iron | BCC | HCP |

Lead | FCC | HCP |

Magnesium | HCP |

**What is the coordination number of BCC?**

8

Coordination number – the number of nearest neighbor atoms or ions surrounding an atom or ion. For FCC and HCP systems, the coordination number is 12. For BCC it’s 8.

### What is the reciprocal lattice for a bcc crystal of lattice parameter?

The reciprocal lattice of a bcc Bravais lattice with conventional unit cell of side is a fcc lattice with conventional unit cell of side 4π/ .

**How many lattice points does a fcc unit cell have?**

(i) One unit cell of a face-centered cubic has 8 lattice points are corners and 6 lattice points at faces, total 14 lattice points.

**How many lattice points are there in bcc?**