PC GAMESS/Firefly TIME DEPENDENT DENSITY FUNCTIONAL THEORY MODULE $TDDFT group required when CITYP=TDDFT (note that CITYP=TDDFT requires DFTTYP to be set in $CONTRL) Current implementation allows the use of only R-DFT references, but can pick up both singlet and triplet excited states. Nuclear gradients are programmed with Firefly version 8.1 onwards. Properties are available using "unrelaxed" density and for "relaxed" density (with Firefly version 8.1 onwards). Due to efficiency considerations, TDDFT is programmed for SAPS (spin-adapted antisymmetrized product) basis only, so you cannot get both singlet and triplet states at once. NCORE = n Omits the first n occupied alpha and beta orbitals from the calculation. The default for n is the number of chemical core orbitals. NSTATE = Number of states to be found (excluding the ground state). ISTATE = State for which properties and/or gradient will be calculated. Only one state can be chosen. MULT = Multiplicity (1 or 3) of the singly excited SAPS (the reference is necessarily single R-DFT). DIAGZN = Hamiltonian diagonalization method. = DAVID use Davidson diagonalization. (default) = FULL construct the full matrix in memory and diagonalize, thus determining all states (not recommended except for small cases). NGSVEC = Dimension of the Hamiltonian submatrix that is diagonalized to form the initial CI vectors. The default is the greater of NSTATE*2 and 10. MXVEC = Maximum number of expansion basis vectors in the iterative subspace during Davidson iterations, before the expansion basis is truncated. The default is the larger of 8*NSTATE and NGSVEC. NDAVIT = Maximum number of Davidson iterations. Default=50. DAVCVG = Convergence criterion for Davidson eigenvectors. Eigenvector accuracy is proportional to DAVCVG, while the energy accuracy is proportional to its square. The default is 3.0E-05. RDTDVC = Flag to read TDDFT vectors from a $TDVEC group in the input file. Default is .FALSE. MNMEOP = Flag to force the use of the minimal amount of memory during the Davidson iterations. This is for debug purposes. The default is .FALSE. MAXGC - maximum allowed number of trial vectors to be routed through GENCON engine, default is 1. If the number of trial vectors is greater than MAXGC, only FASTINTS will be used. The reason is that for moderately contracted GC basis sets like cc-pVXZ, gencon is faster than fastints only for relatively small number of trial vectors (this is by gencon design). On the other hand, for ANO-like basis sets, it is always better to set MAXGC to be equal the number of initial guess vectors, as fastints will be much slower. PRTTOL - threshold for TDDFT csf printout and also for states symmetry determination. Default is 0.05. ISTSYM - symmetry of states of interest. Default is zero, i.e., does not use any symmetry during calculations. Setting this to the desired index of irrep (according to PC GAMESS/Firefly numbering) will solve only for the states of the desired symmetry and exploiting full (including non-abelian) symmetry of molecule, thus significantly reducing computation time. ALTER - flag to modify internal logic of Davidson diagonalization code to use dynamic number of trial vectors. Default is .true. Setting it to .false. will slow-down calculations by forcing DAVIDSON diagonalization code to work exactly as CIS code in the GAMESS (US). TDA - flag to request Tamm-Dancoff approximation to TDDFT (TDDFT/TDA), which is programmed for both pure and hybrid functionals. Default is .false. The state-tracking feature of the PC GAMESS/Firefly' TDDFT code can be activated by selecting negative value of istate in the $TDDFT group. It is intended for geometry optimization of the excited states in the case of root flipping. Note that oscillator strengths printed in the TDDFT summary table are calculated using transition dipoles length form only. ========================================================== $TDVEC group required if RDTDVC in $TDDFT is chosen This is formatted data generated by a previous TDDFT run, to be read back in as starting vectors. ========================================================== Below is the sample input file: $CONTRL SCFTYP=RHF DFTTYP=BLYP CITYP=TDDFT $END $SYSTEM TIMLIM=3000 MEMORY=3000000 $END $BASIS GBASIS=n31 ngauss=6 NDFUNC=1 $END $TDDFT NSTATE=3 ISTSYM=0 ISTATE=1 $END $DATA H2O CNV 2 O 8.0 0.0000000000 0.0000000000 0.7205815395 H 1.0 0.0000000000 0.7565140024 0.1397092302 $END The example of TDDFT/TDA calculations: $CONTRL SCFTYP=RHF DFTTYP=B3LYP CITYP=TDDFT $END $SYSTEM TIMLIM=3000 MEMORY=3000000 $END $BASIS GBASIS=n31 ngauss=6 NDFUNC=1 $END $TDDFT NSTATE=3 ISTSYM=0 ISTATE=1 TDA=.t. $END $DATA H2O CNV 2 O 8.0 0.0000000000 0.0000000000 0.7205815395 H 1.0 0.0000000000 0.7565140024 0.1397092302 $END

- PC GAMESS/Firefly input preprocessing sample
- 64-bit processing support
- Fast Matrix Diagonalization and Inversion
- Spherical Basis Functions
- Fast Two-electron Integral Code
- Additional comments on Two-electron Integral code selection
- Quantum Fast Multipole Method
- Density Functional Theory
- Configuration Interaction Singles
- Time-dependent Hartree-Fock
- CI and Multi-Configuration SCF
- Multi-Configuration Quasi-Degenerate Perturbation Theory
- Extended Multi-Configuration Quasi-Degenerate Perturbation Theory (XMCQDPT)
- PC GAMESS/Firefly' NBO code
- Cube Files
- Multicore, SMP and HTT support
- P2P Parallel Mode Communication Interface, Dynamic Load Balancing, and large-scale MP2 Energy code
- Parallel Linux Instructions: list of supported MPI implementations
- Parallel Windows Instructions: list of supported MPI implementations/bindings

Last updated: March 18, 2009