Next: 19.5.3 Rotating pairs of
Up: 19.5 Restoring and saving
Previous: 19.5.1 Defining the starting
MULTI normally obtains configuration mixing coefficients by a robust
eigenvector solver that converges on the lowest eigenvalues, and
applies a phase convention such that the largest coefficient is forced
to be positive. For most purposes, this approach is satisfactory.
Sometimes one wants a guarantee that the CI vector is phase matched to
that of a previous geometry. This can be achieved by using
SAVE,CI=record.file (see section 19.5.5) in the first job, and in the
The phase convention applied for the rest of the calculation is then
that, for each optimised state, the largest coefficient in the
original CI vector defines the sign of the corresponding coefficient
in the optimised vector.