Electrons with parallel spin would experience greater repulsion than those with opposite spin. This is also the reason why electrons occupying the atomic subshells(1s,2s,2p,3s etc) are always paired in opposite spins.
is that mean 2 orbitals with one occupied by 2 electrons and other with electron occupied singly,
and 2 orbitals both single occupied.
The repulsion between the latter one is greater than the former one?