Hillert Materials Modeling Colloquium series XIV: ab initio thermodynamics for actinide systems
In this seminar Per Söderlind, physicist at LLNL (Lawrence Livermore National Laboratory), will give some examples of actinide materials described by the itinerant 5f-electron. He will also show suggestions for thermodynamic models based on parameter-free first-principles theory.
Time: Tue 2023-06-13 15.00 - 16.00
Location: Zoom
Video link: https://kth-se.zoom.us/j/66414880809
Language: English
Participating: Per Söderlind
The early (or light) actinides Th-Pu have physical properties that are largely understood in terms of the bonding character of dominating 5f electrons. More generally for heavier actinides and compounds, the picture is more complex. In the presentation we will show some examples of actinide materials where the itinerant (bonding) 5f-electron description is appropriate. In addition to ground-state properties such as atomic volume, bulk modulus, and elastic constants, we attempt to model thermodynamics from parameter-free first-principles theory. By combining lattice-dynamics from the self-consistent-phonon method with accurate electronic structure, we determine Gibbs free energies and other thermodynamic properties. Some of these, such as heat capacity or thermal expansion, can be directly compared with experiments while for the Gibbs free energy we use CALPHAD results that are derived from thermodynamically consistent representations of available experimental data. Examples include uranium [1], U-6Nb [2,3], and plutonium [4].
This work was performed under the auspices of the U.S. DOE by LLNL under Contract DE-AC52-07NA27344.