Recent content by Armani

It is not working..maybe I am to confused.

Can anyone explain why the two planes (100) and (010) in the HCP structure have the shortest reciprocal lattice vectors? I mean it says {001}, but why is (001) not included?

If you calculate the structure factor of the BCC lattice using: $$S(hkl)=f{1+exp[-i\pi(h+k+l)]}$$, where f= form factor. The value o f S is zero when the exponential has the value -1, which is whenever the argument is: -i*pi* (odd integer). So we have: S=0 when h+k+l= odd integer S=2f...

Hello, I have to calculate the cut-off energy of Beryllium that have hcp structure with the paramters: a=2.29Å and c=3.58Å. WHAT I HAVE DONE SO FAR: Using plane (100) or (010) Since the formula is: $$E=\frac{1}{2} \times G^2$$ $$G=\frac{2 \Pi}{2d} $$ $$\frac{1}{d^2} = \frac{4}{3} \times...

Okay, thanks for your help.

are those two expressions for ##cos(\phi)## and ##sin(\phi)## already given? Or did you derive them? And thanks:)

(mentor note: thread moved from general to here hence no template) Hi, I need some help with converting this cylindrical vector: $$\vec A = \vec a_r(3*cos(\phi)-\vec a_{\phi}*2r+\vec a_z5$$ into the cartesian: I have found these: where $$A_x =3cos^2(\phi)+2sin(\phi)*r\\...

Hi , I need help with the this exercise: a) Work out all of the canonical commutation relations for components of the operators r and p: [x,y] [x,py] [x,px] [py,pz] and so on. Answer: [ri,pj]=−[pi,rj]=iℏδij [ri,rj]=−[pi,pj]=0 , where the indices stand for x, y, or z and rx=x ry=y rz=z where...