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"There are 6 atoms in the hcp unit cell. The hex shape has six atoms at the points that are direct translations of each other making 1 atom for the top hex and one atom for the bottom hex. That's 2. The atom in the center of the top and center of the bottom are translations giving 1 more. That's 3. Then there are 3 atoms in the middle region of each cell bringing the total to 6."

The answer should depend on how you choose your unit cell.

In the primitive hexagonal cell we have 1 atom at each of the corners of the cell (each is "worth" 1/8) and 1 atom within the cell giving us 2 atoms/unit cell.

(Note: the 'primitive hexagonal cell' above actually refers to the parallelpiped structure that the hexagonal unit cell consists of: the hexagonal 'unit' -it cannot technically be referred to as a unit cell, because unit cells are the most reduced form of the crystal structure- can be divided into 3 parallelepipeds.)

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What is the difference between hcp and ccp closed packing?

HCP (hexagonal close-packed) and CCP (cubic close-packed) are both types of close-packed crystal structures. The main difference lies in the arrangement of atoms - HCP has two alternating layers of atoms, while CCP has three alternating layers. HCP has a hexagonal unit cell, while CCP has a cubic unit cell.


What is the coordination number in hcp?

The coordination number in hexagonal close-packed (hcp) structures is 12. This means that each atom in an hcp lattice is in contact with 12 surrounding atoms.


What is the Lewis structure for HCP?

The Lewis structure for hexagonal close-packed (HCP) structure cannot be accurately represented using the traditional Lewis dot structure as it is a three-dimensional arrangement of atoms. HCP structure consists of layers of atoms arranged in a hexagonal pattern with every other layer shifted by half the length of the unit cell along the c-axis.


What is the lattice parameter of a hexagonal close-packed (hcp) crystal structure?

The lattice parameter of a hexagonal close-packed (hcp) crystal structure is the distance between the centers of two adjacent atoms in the crystal lattice. It is typically denoted as "a" and is equal to 2 times the radius of the atoms in the structure.


What is the packing fraction of the hcp form of titanium?

The packing fraction of the hexagonal close-packed (hcp) structure is calculated as (3 * sqrt(3) * (0.5)^2) / (2) which is approximately 0.74. Therefore, the packing fraction of the hcp form of titanium is around 74%.

Related Questions

What is the difference between hcp and ccp closed packing?

HCP (hexagonal close-packed) and CCP (cubic close-packed) are both types of close-packed crystal structures. The main difference lies in the arrangement of atoms - HCP has two alternating layers of atoms, while CCP has three alternating layers. HCP has a hexagonal unit cell, while CCP has a cubic unit cell.


Volume of a HCP unit cell?

The volume of HCP is 8*pi*r^3 or 25.13*r^3


How do you calculate APF of HCP?

The atomic packing factor (APF) of a hexagonal close-packed (HCP) structure is calculated by taking the volume of atoms in a unit cell divided by the total volume of the unit cell. For HCP, the APF can be determined using the formula: APF = (3 * sqrt(3) * (0.25)) / (2 * sqrt(2)) This simplifies to APF = 0.74


What is the coordination number in hcp?

The coordination number in hexagonal close-packed (hcp) structures is 12. This means that each atom in an hcp lattice is in contact with 12 surrounding atoms.


What is the difference between face centered cubic crystal structure and hexagonal close pack crystal structure?

face centre cubic crystal has eight atoms in each corner and one atom in the centre of cubic unit cell.while hexagonal close packed structuree has only six atoms in corners but no in the centre of cubic cell


What is the Lewis structure for HCP?

The Lewis structure for hexagonal close-packed (HCP) structure cannot be accurately represented using the traditional Lewis dot structure as it is a three-dimensional arrangement of atoms. HCP structure consists of layers of atoms arranged in a hexagonal pattern with every other layer shifted by half the length of the unit cell along the c-axis.


What is the lattice parameter of a hexagonal close-packed (hcp) crystal structure?

The lattice parameter of a hexagonal close-packed (hcp) crystal structure is the distance between the centers of two adjacent atoms in the crystal lattice. It is typically denoted as "a" and is equal to 2 times the radius of the atoms in the structure.


What is the number of spheres in hexagonal close-packed crystal structure?

The hexagonal structure of alternating layers is shifted so its atoms are aligned to the gaps of the preceding layer. The atoms from one layer nest themselves in the empty space between the atoms of the adjacent layer just like in the fcc structure. However, instead of being a cubic structure, the pattern is hexagonal.The hcp structure has three layers of atoms. In each the top and bottom layer, there are six atoms that arrange themselves in the shape of a hexagon and a seventh atom that sits in the middle of the hexagon. The middle layer has three atoms nestle in the triangular "grooves" of the top and bottom plane. Note that there are six of these "grooves" surrounding each atom in the hexagonal plane, but only three of them can be filled by atoms.SAMPLE:· Nickel Arsenide Structure s based on a distorted hcp array of Arsenide anions. By contrast with the wurtzite structure, however, which is also of formula AB, the cations now occupy all the octahedral sites rather than half the tetrahedral holes. There is one octahedral hole for each hcp lattice site, and so the AB stoichiometry is preserved.· Titanium Oxide, TiO2. he anions occupy the hcp lattice, and the cations occupy half of the octahedral holes.LutetiumThalliumTerbium


What is the atomic packing factor of hcp?

.74


What is CPR HCP?

CPR for the Healthcare Provider


Why is coordination number of HCP is 12?

In this, one particle is attached to 6 at the same layer & 3 to the above and below layer.Thus a total of 12.


What is the packing fraction of the hcp form of titanium?

The packing fraction of the hexagonal close-packed (hcp) structure is calculated as (3 * sqrt(3) * (0.5)^2) / (2) which is approximately 0.74. Therefore, the packing fraction of the hcp form of titanium is around 74%.