After this projection has been carried out, the new functions spanning b 12 are no longer eigenstates of the VSCF equation we solved and thus no longer orthonormal among themselves. This can be cured by for example a Gram-Schmidt orhogonalization. However, we follow an approach that preserves as much as possible of the VSCF nature of the basis while maintaining that as many as possible of the basis functions are purely local. VSCF modals found if they had been optimized freely in the entire basis but for the use in dynamics calculation the basis is complete and the localization properties can be used to define physically meaningful basis functions and initial wave functions. This allows for example the wave packet to be initialized to a VSCF state localized to only one of the wells in a double well potential. Fig. shows the VSCF solutions for the one-dimensional double well potential corresponding to the NH 3 inversion mode. In Fig. the VSCF solutions when using the full global basis is shown. Here we observe the well known character of wave functions delocalized over both wells with alternating parity. In Fig. the localized VSCF states obtained by using the split basis is shown. Here it is observed that the VSCF modals are only non-zero in one of the wells a the time. Below the barrier in Fig. , the VSCF solutions are approximately pairwise degenerate, but this is no longer the case for energies higher than the barrier. For the localized solutions in Fig. , the solutions localized in each well are pairwise degenerate for all energies in this system. We note that the low energy localized VSCF modals have no contribution in the b 12 region. This is because the modals which are mainly localized to the b 12 region have a much higher in energy than the modals in the S 1 and S 2 regions.. The two lowest-energy VSCF modals in the b 12 regions are shown in Fig. , together with the six split basis VSCF modals also found in Fig. . From Fig. it can be seen that the b 12 modals are primarily localized at a displacement value around zero where the modals from the S 1 and S 2 sets are zero.