Final_2019_Q2D

[Alex123]

Could somebody please explain why the exponent has \frac{i\pi(h+k+l)}{4} and how this leads to absences when the sum of indices are equal to 2. Shouldn’t it be \frac{i\pi(h+k+l)}{2} for the condition to hold?

[anton-akhmerov]

There’s a typo: \pi should be 2\pi.