The default initial guess for the wavefunctions is calculated from the atomic pseudo-wavefunctions and gives usually excellent results. Good results can also be obtained by using wavefunctions from other calculations with a different cutoff or slightly different geometry. The other initialization method available, starts from random coefficients and should only be used as a last resort. Cases where the default method does not work well are when the molecule has less occupied states than one of the atoms (in this case add some empty states for the molecule), with transition metal ions, or when the additional memory required for the atomic calculation is not available.