We are given two complex numbers:
\[
Z_1 = \frac{1}{2} + \frac{\sqrt{3}}{2}i, \quad Z_2 = -\frac{1}{2} - \frac{\sqrt{3}}{2}i
\]
The problem asks us to find the sum \( w = Z_1 + Z_2 \).
First, add the real parts of \( Z_1 \) and \( Z_2 \):
\[
\frac{1}{2} + \left(-\frac{1}{2}\right) = 0
\]
Next, add the imaginary parts of \( Z_1 \) and \( Z_2 \):
\[
\frac{\sqrt{3}}{2}i + \left(-\frac{\sqrt{3}}{2}i\right) = 0i
\]
So, the sum \( w = Z_1 + Z_2 \) is:
\[
w = 0 + 0i = 0
\]
Thus, the correct answer is \( 0 \).