You maybe got stuck in some of the many local optima that Nurmela 1995 runs into. Genuinely, the best sphere code for 9 points in 4 dimensions is known to have a minimum angular separation of ~1.408 radians, for a worst-case cosine similarity of about 0.162.
You got a lot further than I did with my own initial attempts at random search, but you didn’t quite find it, either.
You maybe got stuck in some of the many local optima that Nurmela 1995 runs into. Genuinely, the best sphere code for 9 points in 4 dimensions is known to have a minimum angular separation of ~1.408 radians, for a worst-case cosine similarity of about 0.162.
You got a lot further than I did with my own initial attempts at random search, but you didn’t quite find it, either.