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== Convergence threshold == === crit_e === === crit_vec === |
tddft: time-dependent density functional theory
Contents
Time dependent DFT/HF calculation. Support Full TDDFT, TDA and RPA.
Quick guides
The following examples give the minimal inputs for starting TD-DFT calculations.
1. Closed-shell Systems : R-TD-DFT
2. Open-shell Systems : U-TD-DFT and spin-adapted TD-DFT for spin-conserving excitations
3. Open-shell Systems : Spin-flip TD-DFT for spin-flip excitations
General keywords
imethod
isf
itda
idrpa
ispa
ialda
thrdab
itest
icorrect
itrans
iro
icv
ioo
iksf
iact
elw
eup
idiag
ndiag
aokxc
Convergence threshold
crit_e
crit_vec
States specification
iext
next
Save eigenvectors
istore
Integer: specify the file no. to store TDDFT information
lefteig
By default, in TD-DFT the left eigenvector X-Y is also stored.
output eigenvector control
nprt
cthrd
TD-DFT/SOC and Property evaluation
nfiles
No. of TD-DFT calculations to be loaded.
isoc
=1, Only work for closed-shell case (NOT recommended!)
=2, General SOC state interaction
=3, just print SOC matrix elements between two spin-free states (without diagonalization Hsoc).
ifgs
=0, default for not including ground state (GS) in SOC treatment; =1, include GS.
imatsoc
Define SOC matrices need to be calculated. Input format looks like
... #SCF calculation for the ground state S0. It is a singlet. $scf spin 0 ... $end #First TDDFT, singlets S0-S9. $tddft imethod 1 isf 0 iext 10 .... $end #Second TDDFT, triplet T1-T10 $tddft imethod 1 isf 1 iext 10 $end $tddft .... imatsoc 7 0 0 0 2 1 1 0 0 0 2 1 2 1 1 1 2 1 1 1 1 1 2 1 2 1 1 2 2 1 1 1 1 2 2 1 2 2 1 1 2 1 1 2 1 1 2 1 2 $end
In this input, 7 means seven of SOC matrices will be calculate (If the number <0, then ALL possible HSOC mat will be printed !). Here, it is very tricky to specify states:
- The string "0 0 0" always treat as the ground state.
For other states, three numbers "n m n" represent "ith-tddft", "symmetry" and "ithstate" respectively. Therefore, the first matrix element "0 0 0 2 1 1" means SOC matrix of <S0|HSOC|T1>. The third matrix element "1 1 1 2 1 1" means SOC matrix <S1|HSOC|T1>. Here, the first "1" in bra state "1 1 1" means the state from first TDDFT calculation. The second and third "1" in the bra state "1 1 1" means this state has spatial symmetry "1" and is the first excited state.
imatrsf
Transition dipole between Spin-free states. The input is similar to imatsoc (but currently selected printing is not implemented). Simply use -1 to print all of them.
imatrso
Define transition dipole moment need to be printed between two SOC-included states. Input format looks like(notice we omit other input in TDDFT module)
$TDDFT ... imatrso 5 1 1 1 2 1 3 1 4 1 5 ... $END
Then, "imatrso" is specified to define transition dipole moments need to be printed. The number "5" require transition dipoles between 5-pairs of states to be print. The following 5 lines define which pairs will be printed. Here, we require transition dipoles between the first state and five states are printed.
idiag
By default, idiag=0 uses full diagonalization (preferred for small model space).
If idiag=1, then TD-DFT/SOC can use Davidson's algorithm also, along with a specification for the no. of states by iexit.
iact
=1, allows to use active space specification for the projected active-orbital SOC Hamiltonian (P*HSOC*P), eup can be specified in (eV) to give a cut off to define active physically interested excited states.
Stability analysis
isab
isave
memory control
memjkop
Others
isgn