Question

Find the electrostatic potential energy of a cubicle configuration

Answer 1

I tried to do this problem by finding the PE at 3 different distances, being the closest 3 points, which are 2 cm away, 2nd closest 3 points which are sqrt(8) cm away and the farthest point which is sqrt(12) cm away. Then I used the formula to find the PE from each charge and added them all up. I keep getting the answer 1.65E-24 J, yet it's not right. Any help would be much appreciated.

Reference https://www.physicsforums.com/threads/electrostatic-potential-energy-of-a-cubical-configuration.793190/