Flashcards in Structure of Crystalline Solids - Chapter 4 Deck (18):

1

## Coordination number of BCC?

### 8

2

## Unit number of atoms in BCC?

### 2

3

## Unit number of atoms formula?

### N = Ni + Nf/2 + Nc/8

4

## Atomic packing factor of BCC?

### 0.68

5

## FCC:

###
Face Centered Cubic Structure

Atoms located at each of the corners and the centers of all the cube faces.

6

## Three Main Crystal structures:

###
FCC - Face-centered structure

BCC - Body-centered structure

HCP -

7

## FCC cube length a?

### a = 2R* Sqrt[2]

8

## FCC coordination number?

### 12

9

## Unit number of atoms in FCC?

### 4

10

## Atomic Packing Factor of FCC?

### 0.74

11

## Atomic Packing Factor(APF)?

###
The APF is the sum of the sphere volumes of all atoms within a unit cell divided by the unit cell volume.

APF = Volume of atoms in a unit cell/total unite cell volume

12

## BCC:

###
Body centered cubic structure:

Atoms located at all eight corners and a single atom at the cubic center.

13

## BCC unit cell length a?

### a = 4R/Sqrt[3]

14

## HCP:

###
Hexagonal close-packed:

The top and bottom faces of the unit cell consists of six atoms that form regular hexagons and surround a single atom in the center. Another plane that provides three additional atoms to the unit cell is situated between the top and bottom planes.

15

## Number of atoms per unit cell for HCP:

### N = Ni + Nf/2 + Nc/6

16

## Unit number of atoms in HCP:

### N = 3 + 2/2 + 12/6 = 6

17

## Coordination number of HCP?

### 12

18