We are developing ab initio methods based on density functional and many body perturbation theory to compute optoelectronic properties of materials and to predict electronic spectra. We have released the WEST code, a massively parallel software for large scale electronic structure calculations based on many-body perturbation theory.
- Implementation and Validation of Fully-Relativistic GW Calculations: Spin-Orbit Coupling in Molecules, Nanocrystals and Solids. P. Scherpelz, M. Govoni, I. Hamada, and G. Galli, J. Chem. Theory Comput. 12 (8), 3523-3544 (2016)
- Large Scale GW calculations. M. Govoni and G. Galli, J. Chem. Theory Comput. 11, 2680 (2015)
G0W0 without empty states
GW and BSE calculations
We have developed ab initio approaches to compute optical absorption and emission spectra of molecules and solids, which are suitable for the study of large systems and give access to spectra within a wide energy range. For absorption spectra, the quantum Liouville equation is solved iteratively within first order perturbation theory, with a Hamiltonian containing a static self-energy operator. For emission spectra, we use a spectral decomposition of the static dielectric matrix as a basis for the frequency dependent density-density response function. Explicit calculations of single particle excited states and inversion and storage of dielectric matrices are avoided using techniques based on Density Functional Perturbation Theory.
- "Implementation and Validation of Fully-Relativistic GW Calculations: Spin-Orbit Coupling in Molecules, Nanocrystals and Solids", P. Scherpelz, M. Govoni, I. Hamada, and G. Galli , J. Chem. Theory Comput. 12 (8), 3523-3544 (2016)
- "Large Scale GW calculations", M. Govoni and G. Galli, J. Chem. Theory Comput. 11, 2680 (2015)
- "Predictive Theory and Modelling of Heterogeneous Interfaces", Tuan Anh Pham, Ph.D. Thesis (2014)
- "GW calculations using the spectral decomposition of the dielectric matrix: Verification, validation, and comparison of methods", T.A. Pham, H.-V. Nguyen, D. Rocca and G. Galli, Phys. Rev. B 87, 155148 (2013)
- "Spectral representation analysis of dielectric screening in solids and molecules", A. Kaur, E.R. Ylvisaker, D. Lu, T.A. Pham, G. Galli and W.E. Pickett, Phys. Rev. B 87, 155144 (2013)
- "Electronic excitations in light absorbers for photoelectrochemical energy conversion: first principles calculations based on many body perturbation theory", Y. Ping, D. Rocca and G. Galli, Chem. Soc. Rev. 42, 2437 (2013)
- "A block variational procedure for the iterative diagonalization of non-Hermitian random-phase approximation matrices", D. Rocca, Z. Bai, R. Li and G. Galli, J. Chem. Phys. 136, 034111 (2012)
- "Solution of the Bethe-Salpeter equation without empty electronic states: application to the absorption spectra of bulk systems", D. Rocca, Y. Ping, R. Gebauer and G. Galli, Phys. Rev. B. 85, 045116 (2012)
- "Improving accuracy and efficiency of calculations of photoemission spectra within many body perturbation theory", H. Nguyen, T. Pham, D. Rocca and G. Galli, Phys. Rev. B. 85, 081101(R) (2012)
- "Ab initio calculations of optical absorption spectra: Solution of the Bethe-Salpeter equation within density matrix perturbation theory", D. Rocca, D. Lu, and G. Galli, J. Chem. Phys. 133, 164109 (2010)