The Rappe Group engages in theoretical investigation to explain and predict the properties of a broad spectrum of fascinating chemical systems, from small molecules to complex lattices.

•New Understanding of Relaxor Ferroelectrics •

Relaxor ferroelectrics have fascinating physical properties exhibitting a stronger piezoelectric effect, a high permittivity value over a broad temperature range, and a strong frequency disperion in dielectric response. Recently we found local dynamics induced by interaction through sharing oxygen atoms in 0.74PbMg1/3Nb2/3O3-0.25PbTiO3, a known relaxor. This transition is analogous to water which exhibits unique dielectric response similar to relaxors. Read more about it from: H. Takenaka, I. Grinberg, and A. M. Rappe, "Anisotropic local correlations and dynamics in a relaxor ferroelectric", Phys. Rev. Lett. 110, 147602 (1-5) (2013).

•Spin Photocurrent•

Pure spin current means that "up" spin and "down" spin move in opposite directions with same magnitude and the total charge current will be zero. Bulk Photovoltaic pure spin current in antiferromagnetics originates from mirror symmetry of two sublattices with different spins. Without strongly spin-orbital coupling or circular light, it can generate pure spin current. Read more about it from: S. M. Young, F. Zheng, and A. M. Rappe, "Prediction of a linear spin bulk photovoltaic effect in antiferromagnets", Phys. Rev. Lett. 110, 057201 (1-4) (2013).

•Bond-valence based interatomic potential for BiFeO3

An atomictic potential for BiFeO3 based on bond-valence and bond-valence vector conservation has been developed. The model reproduces the ferroelectric -to-paraelectric phase trasition in both constant volume and pressure MD simulations. Read more about it from: S. Liu, I. Grinberg, and A. M. Rappe, "Development of a bond-valence based interatomic potential for BiFeO3 for accurate molecular dynamics simulations", J. Phys. Cond. Matt. 25, 102202 (1-6) (2013).


Group meetings are currently held on Tuesdays 1:30 pm at the Theory Conference room (141E)

Physical Chemistry Seminars at Penn Chemistry (Thursdays 1:00pm Carolyn Lynch Lecture Hall)


Y. Kim, B. J. Wieder, C. L. Kane, and A. M. Rappe, "Dirac Line Nodes in Inversion-Symmetric Crystals" Phys. Rev. Lett., 115, 036806 (2015) PDF

Y. Qi, J. M. P. Martirez, Wissam A. Saidi, J. J. Urban, W. S. Yun, J. E. Spanier, and A. M. Rappe, "Modified Schottky Emission to Explain Thickness Dependence and Slow Depolarization in BaTiO3 Nanowires" Phys. Rev. B, 91, 245431 (2015) PDF

F. Wang , and A. M. Rappe, "First-principles calculation of the bulk photovoltaic effect in KNbO3 and (K,Ba)(Ni,Nb)O3-δ" Phys. Rev. B, 91, 165124 (2015) PDF

J. M. P. Martirez , S. Kim , E. H. Morales B. T. Diroll, M. Cargnello, T. R. Gordon ,C. B. Murray , D. A. Bonnell , and A. M. Rappe, "Synergistic Oxygen Evolving Activity of a TiO2 Rich Reconstructed SrTiO3 (001) Surface" J. Am. Chem. Soc. ASAP (2015) PDF

S. Liu, F. Zheng, N. Z. Koocher, H. Takenaka, F. Wang, and A. M. Rappe, "Ferroelectric Domain Wall Induced Band Gap Reduction and Charge Separation in Organometal Halide Perovskite" J. Phys. Chem. Lett. 6, 693 (2015) PDF

N. Moghadam, S. Liu, S. Srinivasan, M. C. Grady, A. M. Rappe, and M. Soroush, "Theoretical Study of Intermolecular Chain Transfer to Polymer Reactions of Alkyl Acrylates" Ind. Eng. Chem. Res. ASAP (2015) PDF

C. Baeumer, D. Saldana-Greco, J. M. P. Martirez, A. M. Rappe, M. Shim, and L. W. Martin, "Ferroelectrically driven spatial carrier density modulation in graphene" Nat. Commun. 6:6136 (2015) PDF

See complete list




requires up to date Java and you might need to add "" from your security exception sites, use at your own risk

The Maxwell-Boltzmann Distribution

Atomic Quantum Mechanics

The group interests cover a wide range of topics involving primarily condensed-matter theory. We employ theory, simulations, and quantum mechanical modeling to understand the physical and chemical properties of bulk, surfaces, and interfaces; ultimately, so that we may take advantage of these properties to address current needs in the field of energy, electronics, sensors, and catalysis.