### Research interests

Quantum many-body problems in physics, chemistry, and materials science.

(Time-dependent) density-functional theory and generalizations.

Development and application of computational methods for the simulation of equilibrium and non-equilibrium properties at the nanoscale.

### Biographical sketch

(2013 - present time) Researcher

CNR-NANO S3

(2011 - 2013) Post-doc

University of California - Department of Chemistry,

Irvine, CA, U.S.A.

(2009 - 2011) Post-doc

University of Missouri - Department of Physics and Astronomy,

Columbia, MO, U.S.A.

(2008 - 2009) Post-doc

Free University Berlin - Department of Theoretical Physics,

Berlin, Germany.

(2008) Ph.D. in Theoretical Physics

Free University Berlin - Department of Theoretical Physics,

Berlin, Germany.

### Selected publications

T. Gould and S.P., "Density-Driven Correlations in Many-Electron Ensembles: Theory and Application for Excited States",

* Phys. Rev. Lett. * ** 123 **, 016401 (2019)

T. Gould and S.P., "Hartree and Exchange in Ensemble Density Functional Theory: Avoiding the Nonuniqueness Disaster",

* Phys. Rev. Lett. * ** 119 **, 243001 (2017)

S.P., G. Vignale, and F.G. Eich, "U(1) X SU(2) gauge invariance made simple for density functional approximations",

* Phys. Rev. B * **96**, 035141 (2017)

K. Burke, A. Cancio, T. Gould, and S.P., "Locality of correlation in density functional theory", * J. Chem. Phys.* **145**, 054112 (2016)

S.P., F. Troiani, C.A. Rozzi, and G. Vignale, "*Ab-initio* theory of spin-entanglement in atoms and molecules", *Phys. Rev. B* **91**, 075109 (2015)

S.P., A. Delgado, J. Robin, L. Freimuth, J. Christoffers, C. Lienau, and C.A. Rozzi, "Charge separation dynamics and opto-electronic properties of a diaminoterephthalate-C_{60} dyad", Adv. Funct. Mater. doi: 10.1002/adfm.201402316 (2014)

F.G. Eich, S.P., and G. Vignale, "Transverse and longitudinal gradients of the spin magnetization in spin-density-functional theory",

*Phys. Rev. B* **88**, 245102 (2013)

E. Räsänen, C.A. Rozzi, S.P., and G. Vignale, "Electron-Electron Interactions in Artificial Graphene", *Phys. Rev. Lett.* **108**, 246803 (2012)

S.P., G. Vignale, and I.V. Tokatly, "Quantum continuum mechanics in a strong magnetic field", *Phys. Rev. B* **84**, 245118 (2011)

S.P., C.R. Proetto, A. Floris, A. Sanna, C. Bersier, K. Burke, and E.K.U. Gross, "Exact Conditions in Finite-Temperature Density-Functional Theory", *Phys. Rev. Lett.* **107**, 163001 (2011)