Our implementation of the DFTB method can perform single point calculations, geometry optimizations, transition state searches, frequency calculations, and molecular dynamics. Molecules as well as periodic systems can be handled ensuring a smooth link with our full DFT codes ADF and BAND. It can be used as a stand-alone command line program, or from the graphical interface.
The DFTB program is orders of magnitude faster than DFT, but requires parameter files to be installed for all pair-wise combinations of atoms in a molecule. Many elements can be handled with the parameter sets included in the distribution. Alternatively, sets of parameters in the SKF format can be downloaded and used from third party sources.
Three models within the DFTB framework are available: standard DFTB, SCC-DFTB (DFTB with self-consistent-charge correction), and DFTB3 (SCC-DFTB with third-order correction). As they have been respectively parametrized, it is important to specify a proper parameter set when applying one of these models.
- New features:
- spin-polarized calculations
- DFTB3 for periodic systems
- l-dependent SCC-DFTB and TD-DFTB
- user defined masses in the input file, allowing the calculation of systems with different isotopes of the same element
- calculation of fat-bands
- massively improved performance of the D3-BJ dispersion correction for periodic systems
- improved performance of lattice optimizations
- Mayer bond order analysis
- interface to the NBO6 program
- support for parameter sets with only partially present repulsive potentials (e.g. halorg-0-1)
- support for restarting geometry optimizations
- reading of initial Mulliken charges from the input file
- All DFTB.org parameter sets are now Creative Commons licensed and no longer require a special license agreement.
The following new parameter sets are available:
- 3ob-ophyd: modified O-P for 3ob (improves description of pentavalent phosphorus species)
- auorg: for gold-thiolate compounds
- borg: boron systems (solids and molecules)
- halorg: for halogens
- magsil: for chrisotyle nanotubes
- New defaults:
- the default model Hamiltonian is now SCC-DFTB (used to be DFTB0)
- k-space sampling is now disabled by default for periodic systems (only gamma-point will be sampled)
- fixed an issue with the band structure calculation for SCC-DFTB
- fixed lattice optimization for Gamma-only periodic DFTB calculations