The ab initio computations suggest that transitions to a stabilised state (with a p-type orbital perpendicular to the coordinate to the coat molecule) may lead to a shorter lifetime for an ensemble of 87 Rb atoms than transitions to a destabilised state (with a p-type orbital parallel to the coordinate to the coat molecule); the stabilised atomic states have a negative interaction energy with the coat molecules (i.e., favourable physisorption for a bound species) and therefore a larger rate of decoherence, whereas the destabilised states have a positive interaction energy (unfavourable physisorption). The computed adsorption energies are shown in Table . Population of the destabilised state would preserve the spin polarisation by avoiding collisions with the cell wall coat, which lead to decoherence, as the destabilised state cannot physisorp on to the cell wall coat.