close packing in crystals

Assumption - It is assumed that the atoms are hard spheres of identical size. Packing is done in such a way that they occupy maximum available space. This type of packing is called close packing . The packing of the spheres of equal size latices pla..

Noble gases - All noble gases crystallize in ccp structure except helium which has hcp structur..

In two-dimensional packing, hexagonal close packing is more efficient. In three dimensions the second layer spheres are placed in the A voids and B voids are unoccupied. In the second layer there are C and D voids. The third layer is placed such that it covers the C v..

Derivation of the Relationship Between Radius r of the Octahedral Void and the Radius R of the Atoms in the Close Packing. - Derivation of the Relationship Between Radius r of the Octahedral Void and the Radius R of the Atoms in the Close Packing. A sphere fi..

a) Square close packing - Particles when placed in the adjacent rows show a horizontal as well as vertical alignment and form squares. b) Hexagonal close packing - Packing in every next row are placed in the depression between the particles of the ..

Derivation of the Relationship Between Radius r of the Tetrahedral Void and the Radius R of the Atoms in the Close Packing. A tetrahedral void may be represented in a cube as shown in the below figure. fig 2.12 - Tetrahedral void The three spheres form the triangular ba..

A sphere fitting into the octahedral void is shown by shaded circle. A sphere above and a sphere below this small (shaded) sphere have not been shown in the figur..

The tetrahedral arrangement of four ligands surrounding the metal ions is as shown in the figure. fig 10.2 - Tetrahedral arrangement of four ligands surrounding the metal ions It is clear from the figure that none of the d-orbitals point exactly towards the ligands. The three d-orbitals d x y , d y..

In a crystalline solid, the constituent particles (atoms, ions or molecules) are arranged in a regular order. An interaction of a particular crystalline solid with X-rays helps in investigating its actual structure. Crystals are found to act as diffraction gratings for X-rays and this ind..

Efficiency of packing in hcp and ccp structures - We have discussed earlier that in both type of close packing (hcp and ccp) approximately amount of the available volume is occupied by spheres (atom..