CMSP Online Seminar: Michele Pavanello

20 January at 16:00 GMT+2

20/1/2022

ICTP-EAIFR looks forward to welcoming Michele Pavanello of Rutgers University, USA for a talk entitled "The World of Molecular Condensed Phases Revealed by Subsystem Density Functional Theory." Taking place on Thursday, 20 January at 16:00 GMT+2, all are welcome to attend: registration is free.

Abstract: Condensed phases involving molecules are ubiquitous in chemistry, physics, and material science. Examples are molecular liquids, molecular crystals and interfaces between conventional solids and molecular systems. To understand and predict the properties of such systems Density Functional Theory (DFT) is almost always involved. DFT, however, carries some inconvenient limitations. A crippling one stems from its focus on the whole system rather than on the molecular building blocks resulting in the impossibility to relate the properties of the single molecules with the properties of the condensed phase. Another, more obvious limitation is its computational cost which scales cubically with system size. A much more mature view of molecular condensed phases is one that recognizes the molecules as fundamental building blocks. In this talk I will show that subsystem DFT achieves two important goals: (1) reduction of the computational complexity to linear scaling with the number of molecules in the system; (2) the ability to understand the physics of processes occurring in condensed phases in terms of embedded subsystems and their interactions with the environment (i.e., other subsystems). I will show a number of interesting examples from dynamics on the ground state BO surface to excited electronic states via a real-time subsystem TDDFT treatment. For systems such as liquid water, we have determined the structure, dynamics, optical spectrum and ionization processes. I will also touch upon other case studies related to electronic processes at molecule-surface interfaces.