S

> The value of the spin quantum number \(S\) is given by this option. The default is determined by the value of the multiplicity. This is used for two things: (1) determining the phase of the redundant half of the CI vector when the \(M_s = 0\) component is used (i.e., MS0 = `TRUE`), and (2) making sure the guess vector has the desired value of \(\langle S^2\rangle\) (if CALC_S_SQUARED is `TRUE` and ICORE = `1`).

> - Type: double
> - Default: 0.0