Workshop on ab initio calculations in geosciences
Invited speakers:
- Sandro Jahn, Geoforschungszentrum Potsdam, Germany.
- Nico de Koker, Bayerisches Geoinstitut, Universität Bayreuth, Germany
- Kanani K. M. Lee, Yale University, USA.
- Taku Tsuchiya, Ehime University, Japan.
Scope:
The methods based on numerical quantum mechanical computation (i.e. ab initio approach) became very usefull as a research tool in the solid state physics. These methods provide access to the wide variety of material properties like elastic constants, phonon dispersion relations, electronic structure and many others. Furthermore, not only zero temperature, zero pressure but also high pressure, elevated temperature conditions can be targeted with these methods.
These characteristic make ab initio methods quite valuable also for mineralogy, since thay can provide complementary data on mineral properties in extreme conditions found in the Earth's interior
We intend the workshop to be mainly an opportunity for people entering the field to learn the techniques and tools of this type of calculations, but also a forum for scientists to present and discuss their original research.
One method of calculating phonons in crystalline systems with appreciable accuracy is to use the Hellmann-Feynman forces found in ab initio calculations, based on supercell approach. The DFT ab initio codes, such as VASP, Wien2k, provide tools to derive complete sets of mentioned atomic forces even as a functyionof pressure. Next, using the PHONON code the harmonic phonon properties of bulk crystals, without and with defects, surfaces, interfaces and similar systems can be treated. Furthermore, the quasiharmonic approximation allows to treat the mentioned systems at finite temperature, which is a necessary step for extending DFT results to describe the systems in a complete manner.
Tutorials on the VASP and PHONON code will allow the participants to learn the parctical way one may carry on the calculations of crystalline materials in the pressure-temperature space.