Lowest energy orientation of the dumb bell mass system surrounded by electron cloud:
1)Cloud’s R < the separation h between clouds: a>0
Tetha = 2n*pi, n = 0,1,2,3,…
(cos(tetha) = +1 => Quadrupole moment < 0)
2)Cloud’s R = the separation h between clouds: a=0
Quadrupole moment = 0 -> any orientation has no influence due to quadrupole moment
3)Cloud’s R > that separation h between clouds: a<0
Tetha = n*pi, n = 1,3,5,…
(cos(tetha) = -1 => Quadrupole moment < 0)