Abstract

Semiempirical electronic structure theory methods are the physically motivated approach to bridge the gap between ab initio quantum mechanical and classical methods. However, their applicability has often been hampered by relatively low accuracy and the small number of parametrized elements. The extended tight-binding (xTB) methods that were developed during the past six years contributed to overcoming this obstacle. Via a purpose-specific element-wise parametrization strategy, parameters for most elements of the periodic table could be obtained,while providing methods with sufficient accuracy for exploratory calculations. In this talk, the development of the xTB methods will be reviewed and exemplary applications will be highlighted. Future directions in the development and application of semiempirical methods will also be discussed.