For further details regarding the calculation of weights in CASVB, see
T. Thorsteinsson and D. L. Cooper, J. Math. Chem. **23**, 105-26 (1998).

Calculates and outputs weights of the structures in the valence bond
wavefunction . *key* specifies the definition of
nonorthogonal weights to be used, and can be one of:

`CHIRGWIN`- Evaluates Chirgwin-Coulson weights (see:
B. H. Chirgwin and C. A. Coulson, Proc. Roy. Soc. Lond.
**A201**, 196 (1950)). `LOWDIN`- Performs a symmetric orthogonalization of the structures and outputs the corresponding weights.
`INVERSE`- Outputs ``inverse overlap populations" as in
G. A. Gallup and J. M. Norbeck, Chem. Phys. Lett.
**21**, 495-500 (1973). `ALL`- All of the above.
`NONE`- Suspends calculation of structure weights.

molpro@molpro.net 2018-06-21