How to calculate the PKA velocity in a crystal?

[Aadrych]

Hi,

I need to calculate the velocity of a particle acting along a specific crystal direction.
For example a PKA acting along the [135] direction in a crystal with a certain velocity, how do I find the velocity along the x, y and z direction?
Also if I am looking at a hcp crystal, would this calculation change?

Thanks in advance.

 

[gtoguy97]

To calculate the velocity of a particle acting along a specific crystal direction, you will need to know the crystal lattice parameters (a, b, c) and the direction cosines (α, β, γ) for the crystal. You can then use the following equation to calculate the velocity along each direction:vx = vcos(α)vy = vcos(β)vz = vcos(γ)If you are looking at an hcp crystal, these equations would still apply, however the direction cosines for the hcp crystal would be different from those of the cubic crystal.