Hi friends, Tomorrow (Wednesday), Prof. Jeff Neaton of Cal will be giving the theochem seminar. It will be the *only* theochem seminar this year held at Harvard (the rest are at MIT or BU). The talk will be in Pfizer at *4:15pm*. The talk will be in Pfizer at *4:15pm*. See title and abstract below. Cheers, Nicolas *Excited States And Energy Conversion In Organic Crystals And At Interfaces Via First-Principles Methods* *Prof. Jeffrey Neaton* Department of Physics University of California, Berkeley *Wednesday, November 16, 2016* *4:15 – 6:15pm* *Pfizer Lecture Hall* *Mallinckrodt Building (12 Oxford Street)* Organic crystals and hybrid interfaces are highly tunable, diverse classes of cheap-to-process materials with promise for next-generation optoelectronics. Further development of new materials requires new intuition that links atomic- and molecular-scale morphology to underlying excited-state properties and phenomena. I will review ab initio methods for calculating excited-state and transport properties of crystalline solids and interfaces, and show several applications, where we have used these methods to explain or drive new experiments. Specifically, I will cover the use of first-principles density functional theory with tuned hybrid functionals, and many-body perturbation theory within the GW approximation and the Bethe-Salpeter equation approach, for computing and understanding spectroscopic properties of acene crystals, including new insights into measured multiexciton phenomena such as singlet fission; as time permits, I will additionally share preliminary results on low-dimensional materials, such as 2d chalcogenides, and halide perovskites. I will also discuss multiple approaches to calculating level alignment at metal-molecule interfaces, where we have recently generalized optimally-tuned range-separated hybrid functionals to treat the electronic structure with accuracy comparable to many-body perturbation theory, and describe implications for single-molecule junction transport measurements.