So, I'm creating a program that would represent a given atom (also different isotopes) in 3d view. I'd need some kind of formula to calculate the position of protons and neutrons to form a nucleus.
A = The number of balls (=protons and neutrons), can vary from 1 to 250. When A is 1, ball's coordinates are 0, 0, 0. With 2 balls coordinates could be for example -r, 0, 0 and r, 0, 0. Balls colliding at (0, 0, 0). And so on. Protons and neutrons should preferably be placed like in Atomic packing factor FCC so that the nucleus would be as tight as possible.
A formula with 'n' being the index of the ball and 'A' being the number of balls in nucleus would be perfect. The result should be a 3D point (x, y, z). The radius of the balls is 1.
I'm not quite sure if it's even possible to make? Also I don't need all the variants, anything that works and looks tolerable will be fine. I'm not even quite sure if this should be asked here or elsewhere.. so sorry about that. Thank you for all the help!
an example image(http://www.alternativephysics.org/book/img/ANuc-ball-nucleus.jpg)
A huge edit!
I found a list http://www.randomwalk.de/sphere/insphr/sequences.txt that I can use to get first 72 nucleus. The algorithm used to calculate those values is exactly what I was looking for but I think I can live with this, atleast for now. :)