Warning
PTB (for the publication, press here) is now natively available in xtb>=6.7.0 (see here for details).
This program is therefore considered obsolete and should not be used anymore for standard purposes.
A density matrix (P) tight-binding (TB) method based on a polarized valence double-zeta basis set. It is available for all elements and structures until Z = 86.
In this development version, before execution, two files have to be given:
The .atompara file containing all empirical parameters. If no specific location is given via a -par flag, it is assumed to be located in the $HOME directory (e.g., ~/.atompara).
An individual location can be defined via the -par <path of .atompara> command.
The .basis_vDZP file contains the vDZP basis set in the correct format. Its file location can be defined via the -bas flag, otherwise it is assumed to be in
$HOME (e.g., ~/.basis_vDZP).
Molecular (total) charge can be incorporated via the presence of a .CHRG file. A similar procedure follows with the number of unpaired electrons (.UHF),
eventhough PTB is mainly developed for closed-shell systems.
You can use a statically-linked release binary (recommended), but you can also build it with the source code.
git clone https://github.com/grimme-lab/ptb.git
cd source
You can the build the project via make.