DFTB+ 1.0

This is the first offically released version of DFTB+, distributed also in source form. For the full list of features see the overview page about DFTB+.

Compilation

DFTB+ 1.0 had been successfully compiled and tested (using the tests in the autotest system) on the following architectures:

Machine	System	Compiler	BLAS/LAPACK	Notes
i686	Linux	Intel Fortran (32-bit) 9.1	MKL 8.0
i686	Linux	g95 (build 20060727)	ATLAS
x86_64	Linux	Intel Fortran(em64t) 9.1	MKL 8.0
ia64	Linux	Intel Fortran (Itanium) 9.0	MKL 8.0
alpha	OSF1	Compaq Fortran X5.3-1155	NETLIB (reference) BLAS/LAPACK

 

Changes

Since version 0.9, the following features had been added or changed. For a detailed description of the new keywords and features, see the manual. Especially make sure, that you consult the manual about the OldSKInterpolation keyword, since it influences your numerical results.

The changed keywords (except ParserVersion) can be automatically handled by the compatibility mode of the parser, when setting 'ParserOptions/ParserVersion = 2'. This instructs DFTB+ to interprete the input as if it had been written for the parser of DFTB+ 0.9 (ParserVersion = 2), instead of 1.0 (ParserVersion = 3). Independently of the compatibility mode, the processed input written into dftb_pin.hsd always contains the input in the current format.

Keyword OrbitalResolvedSCC added:

In order to maintain a better compatibility to the old DFTB code and the old SK-files the default behaviour of DFTB 1.0 changed: Per default only the Hubbard U value for the s-shell is used for all angular momenta. A truly orbital resolved calculation (with different Hubbard Us for each shell) can be achieved by setting OrbitalResolvedSCC = Yes. Please make sure, that your Slater-Koster files contain the right Hubbard Us for that.

Keyword Variational removed.

DFTB+ 1.0 is using only variational total energy calculation. There is no way to use the old stationary energy calculation. (For a converged SCC calculation, the results should be the same.

Keyword IndependentKFilling added.

For periodic systems you can specify, if the filling in the K-points should be done separately or by using a common Fermi level for each K-point. (Mostly used for defect calculations.)

Keyword OldSKInterpolation added.

DFTB+ 1.0 uses slightly different interpolation scheme for the Slater-Koster integral table, yielding somewhat better behaving forces. The differences in the results should be below the accuracy of the method. If you want to use the old scheme, you have to set this option to Yes. (This is, however, discouraged, since the old interpolation algorithm might be removed from the code in future releases.)

Keyword Dispersion added.

DFTB+ is able to calculate dispersion correction due to van der Waals forces.

Keyword InitalSpin introduced.

You can specify the initial spin distribution (e.g. anti ferro magnetic ordering for your system).

Keyword Type2FileNames added.

If your Slater-Koster files are named after well defined pattern (containing the name of the element pairs), you can specify the pattern, instead of specifying all Slater-Koster files explicitely.

Keyword SupercellFolding added.

It enables you to specify Monkhorst-Pack and alike K-point sets automatically

Output file names changed

In order to have a consequent naming strategy, the following output files had been renamed. (The appropriate keyword change is indicated in paranthesis.)

• tagged.out into autotest.tag (WriteTaggedOut into WriteAutotestTag)
• band.dat into band.out (WriteBandDat into WriteBandOut)
• eigenvec.dat into eigenvec.out (PrintEigenvectors into WriteEigenvectors)

Keyword InputVersion changed to ParserVersion

This is the only change input, which can not be handled by the compatibility mode of the parser. If occuring in your input, please, change it manually.

Autotest system is based on standard Slater-Koster files

The autotest system is based on standard set of Slater-Koster files as distributed from the website dftb.org. You have to register for them separately.