For any N>1, let C(N) denote the infimum of the Coulomb energy
E(z1,…,zN):=1≤i<j≤N∑∥zi−zj∥1
where z1,…,zN ranges over the unit sphere S2. Establish upper and lower bounds on C(N) that are as strong as possible. What type of configurations z1,…,zN come close to achieving the infimal (ground state) energy?