fill_pp_doubles_guesses

libadcc.fill_pp_doubles_guesses(guesses_d: List[libadcc::Tensor], mospaces: libadcc::MoSpaces, df02: libadcc::Tensor, df13: libadcc::Tensor, spin_change_twice: int, degeneracy_tolerance: float) → int

Fill the passed vector of doubles blocks with doubles guesses using the delta-Fock matrices df02 and df13, which are the two delta-Fock matrices involved in the doubles block.

guesses_d Vectors of guesses, all elements are assumed to be initialised to zero and the symmetry is assumed to be properly set up. mospaces Mospaces object df02 Delta-Fock between spaces 0 and 2 of the ADC matrix df13 Delta-Fock between spaces 1 and 3 of the ADC matrix spin_change_twice Twice the value of the spin change to enforce in an excitation. degeneracy_tolerance Tolerance for two entries of the diagonal to be considered degenerate, i.e. identical. Returns The number of guess vectors which have been properly initialised (the others are invalid and should be discarded).