User Guide to Semiempirical Tight Binding¶
This user guide focuses on the semiempirical quantum mechanical methods GFNn-xTB, their descendants, and corresponding composite schemes as implemented in the xtb (extended tight binding) program package.
We provide a number of detailed guides dealing with common task that can
be performed easily with the xtb program.
All guides are usually structured the same way, starting with some simple
examples using only the commandline and the default settings followed
by a trouble shooting section.
Detailed inputs are provided in a ready to use fashion to solve some
more special but still common tasks with xtb together with some
insights into the theory used behind the scences.
xTB in Other Quantum Chemistry Programs¶
The xTB-methods are now officially available in other quantum chemistry programs!
- in Orca 4.2 an IO-based interface to the
xtbbinary is available - AMS 2019 implements GFN1-xTB in their DFTB module
- the entos program implements GFN1-xTB (also available in the webinterface)
We missed your project here? No problem, just give us hint at the mailing list or open an issue at github.
Quickstart
Guides
- Singlepoint Calculations
- Properties
- Geometry Optimization
- Exploration of the potential energy surface (PES)
- Implicit Solvation
- Calculation of Vibrational Frequencies
- Molecular Dyamics Simulations
- Meta-Dynamics Simulations
- Growing String Method
- Periodic Boundary Conditions
- External Potentials and Embedding
CREST
- Introduction to CREST
- CREST Versions and Changelog
- Basic Usage
- Example applications
- iMTD-GC conformational search
- MF-MD-GC conformational search
- Sorting an ensemble
- Comparing two ensemble
- Constrained conformational sampling
- Sampling of noncovalent complexes and aggregates (NCI mode)
- Molecular prototropy screening
- Property calculations on final ensemble
- Dry run to check settings prior to calculations
API