SKF File Download

Welcome to the SKF File Download page. Pick a parameter set, choose the elements you need (type symbols, click on the periodic table, or grab a preset), and we’ll bundle the matching Slater–Koster files into a ZIP for you in the browser.

The available parameter sets are PRIOR, PTBP, and QN+Rep, all introduced in the article PTBP. Although these parameter files were not specifically optimized for compounds, they still demonstrate relatively reliable performance, as shown in Part 3.2 of PTBP (benchmarks on hydrides, nitrides, oxides, and fluorides).

The full sets are also archived on Zenodo: doi.org/10.5281/zenodo.10677795. The code for processing the parameterization can be found at PTBP_lab.

Tip

Coming from the periodic table on PTBP_Lab? Click an element there and you’ll arrive here with that symbol pre-filled.

Options

1. Select parameter set

PTBP (default): the parameter set generated in PTBP.
QN_rep: electronic parameters \(r^0_\mathrm{w}\), \(r^0_\mathrm{d}\), and \(p\) are taken from QUASINANO2013 (J. Chem. Theory Comput. 2013, 9, 4006-4017); the repulsive part is fitted as in PTBP.
PRIOR: \(r^0_\mathrm{w}\) and \(r^0_\mathrm{d}\) are restricted to 2 and 4 times the covalent radius \(r_\mathrm{cov}\), with \(p=2\), and the repulsive part is fitted as in PTBP.

Note

The large exponent \(p\) inside the QN_rep confinement potential \(\left( \frac{r}{r_0} \right)^p\) tends to cause convergence problems while generating SKFs. The QN_rep set therefore contains all elemental files but only a limited selection of heterogeneous files — those used for the binary benchmarks in PTBP.

2. Choose elements

Type symbols separated by commas or spaces, click cells in the periodic table, or pick a preset. Selections stay in sync.

STO coefficients are downloaded automatically with each request from ptbp_wfc.hsd.

3. Generate and download

Tip: press Enter in the elements box to start.

How to use the SKFs in DFTB+

After unzipping PTBP_skfs.zip, point your DFTB+ input file at the folder. A typical dftb_in.hsd snippet:

Hamiltonian = DFTB {
  SlaterKosterFiles = Type2FileNames {
    Prefix = "/path/to/PTBP_skfs/"
    Separator = "-"
    Suffix = ".skf"
  }
  MaxAngularMomentum {
    C = "p"
    H = "s"
    O = "p"
    # ...
  }
  # PTBP recommends loading the STO coefficients:
  # download ptbp_wfc.hsd alongside the SKFs and <<+ it here.
  <<+ "ptbp_wfc.hsd"
}

The expected file naming is <elem1>-<elem2>.skf (e.g. C-H.skf, H-C.skf — both directions), which is what the ZIP we generate above contains.

The DFTB+ user manual has the authoritative reference: https://dftbplus.org/documentation.