In this paper, we proposed a brand new nuclear {N,n//6} QM. It showed that like the Sun-planet system, the atom’s nucleus-electron system also follows the {N,n//6} QM. By using the nucleus-electron system’s interior {N,n//6} QM with the ground state electron’s orbit as e1{0,1}, the nuclides of hydrogen (Z=1), He (Z=2), Li (Z=3), Ne (Z=10), Fe (Z=26), Pd (Z=46), and Og (Z=118) atoms have the interior QM structure (in size) of e1{-3,1//6}, e1{-3,2//6}, e1{-3,3//6}, e1{-3,6//6} = e1{-2,1//6}, e1{-2,2//6}, e1{-2,3//6}, and e1{-2,6//6} = e1{-1,1//6}, respectively. Although all nucleons in those nuclides structured in {N,n//6} QM, this property actually is a hidden property (like a “recessive gene”) that only showed up at the interior e1{N,n//6} QM using electron’s n=1 shell as the reference point. This is because the strong EM-force shrank the orbital r1e to r1e/Z. The study revealed that Fe atom’s nucleus is the only one that has the 100% nucleon occupancy in the n = 1 nucleon orbital shell space (among the size n=2 nuclides from Z = 11 to Z = 26), so that Fe element’s nucleus has the most stable nuclear {N,n//6} QM structure in comparison to that of its adjacent elements. This result explains why Fe is more abundant than its adjacent elements, and why Fe atom is the heaviest nucleus that a nuclear fusion reaction can go without adding extra energy. This is exactly like why the inert element Ne is chemically most stable among the electron period 2 elements, because it has the outmost electron shell completely filled (or it has the 100% electron occupancy in the n=2 electron orbital shell space). This analysis revealed that the atom’s nuclear {N,n//6} QM structure stability played an important role in determining the abundancy of each element in our universe. Therefore, the nuclear {N,n//6} QM structural analysis significantly improved our knowledge on the nuclear physics. Further analysis showed that although the {N,n//q} QM structures of both atom’s nucleus shell and atom’s electron shells are primarily in {N,n//6} QM at the low Z#, at the high Z#, both of them shifted to the {N,n//7} QM. Another analysis revealed that {-10,1//6} is the maximum (ever-possible) size of an atom. It also revealed that although {N,n//6} is the fundamental {N,n//q} QM structure in our universe, the disruption of either the primary EM-force or G-force formed {N,n//6} QM structure will form {N,n//q} QM structure with q quantum number other than 6.