##master-page:HelpTemplate ##master-date:Unknown-Date #format wiki #language en #Please change following line to BDF module name = tddft: time-dependent density functional theory = <> {{{ 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 ]] 4. [[ TD-DFT with SOC ]] == General keywords == === imethod === === isf === === itda === === idrpa === === ispa === === ialda === === thrdab === === itest === === icorrect === === itrans === === iro === === icv === === ioo === === iksf === === iact === === elw === === eup === === idiag === === ndiag === === aokxc === == 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 == === ifgs === === nfiles === === 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 === irsf === Unused. === irso === === insf === === inso === === 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. Here, it is very tricky to specify states. First, "0 0 0" always treat as the ground state. Second: 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 . The third matrix element "1 1 1 2 1 1" means SOC matrix . 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 === Unused. === imatrso === Define transition dipole need to be printed between to states. Input format looks like(notice we omit other input in TDDFT module) {{{ $TDDFT ... irso 1 imatrso 5 1 1 1 2 1 3 1 4 1 5 ... $END }}} Here, "irso" is set to 1 to enable transition dipole moment calculation. Then, "imatros" 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 ground state and five low-lying states are printed. === imatnsf === === 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 === === ivo ===