Reciprocal Lattices and Ewald Sphere: Solving for a* and c* in a Tetragonal Cell

  • Thread starter Thread starter PhysicsKid99
  • Start date Start date
  • Tags Tags
    Reciprocal
AI Thread Summary
To find the reciprocal lattice vectors a* and c* for a body-centered tetragonal cell with parameters a=3Å and c=5Å, the correct calculations yield a* = 1/3 and c* = 1/5. The radius of the Ewald sphere is determined using the formula radius = 1/λ, resulting in a radius of 2/3 for λ = 1.5. The discussion highlights confusion regarding the scale of the drawings, suggesting that the reciprocal lattice may actually represent a face-centered tetragonal lattice. Participants are encouraged to share their working solutions to clarify discrepancies in the calculations.
PhysicsKid99
Messages
3
Reaction score
0

Homework Statement


I have to draw a reciprocal lattice of a tetragonal cell with parameters a=3A and c=5A, a body-centred lattice. How do I find a* and c*? I also have to draw an Ewald sphere, and lamda=1.5. However, if I use my solutions (I think they're wrong, see below) I get something that is impossible to draw because the scale is huge.

Homework Equations


Radius of E sphere= 1/lamda

The Attempt at a Solution


a*=1/9 and c*= 1/25, the radius= 2/3
 
Physics news on Phys.org
Not an area I know anything about, but from a little reading it seems the reciprocal lattice will be a face-centred tetragonal lattice, yes?
The parameters are obtained by dividing vector cross products by the scalar triple product.
Please post your working for your attempted solution. (I get a different answer.)
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top