RX at a fairly large internuclear distance. The process is driven by dipolar coupling, and is therefore related to internuclear distances. For formula 7, there is no generally applicable expression for the internuclear potential. There is one nodal plane containing the internuclear axis, if real orbitals are considered. Exchange energy splittings are very elusive to calculate for molecular systems at large internuclear distances. Internuclear ophthalmoplegia is a disorder of conjugate lateral gaze. As follows from the BPP theory, measuring the T times leads to internuclear distances r.