Closed-shell Systems : R-TD-DFT
This gives a R-TD-DFT (imethod=1,itda=0) for singlet-singlet (isf=0) transitions using Davidson iterative diagonalization (idiag=1). In each irreducible representations, the lowest 10 states are calculated.
$TDDFT IMETHOD 1 ISF 0 ITDA 0 IDIAG 1 iexit 10 $END
The algorithm used in TD-DFT is the same as in the ground state calculations. If direct SCF is used.
$xuanyuan directhf $end ...
then TD-DFT also uses direct algorithm. The memory for JK operators can be changed by using MemJKOP.
$TDDFT ... MemJKOP 2048 ... $END
If the ERI is stored, then integral transformation should be carried out before TDDFT
$TRAINT TDDFT (or UTDDFT for RO/U case) ORBI hforb $END