# Yasuyuki Ishikawa

*Professor*

**Contact**Office: FB 319 – located on the third floor of Facundo Bueso Bldg

Email: yishikawa@uprrp.edu

Phone: 787-764-0000 ext. 5908

**Education**Ph.D., University of Iowa, 1976.

Postdoctoral Fellow, Rutgers University, 1976-78.

Wissenschaftlicher Mitarbeiter, Universität Siegen, Germany, 1978-80.

**Research Interests**

Relativistic Many-Body Theory; Ab Initio Monte Carlo/Molecular Dynamics Simulation of Many-Body Systems; Theoretical modeling and simulation of electrochemical systems

**Research Focus**

*Relativistic many-body theory for atoms and molecules*: Heavy atom species are many-electron systems with complicated state structures which push conventional computational techniques to their limits. During the last two decades, we have been trying to find suitable fully relativistic SCF and many-body theories (e.g., relativistic many-body perturbation theory and relativistic coupled cluster theory) for atoms and molecules as a means of turning physical pictures of electronic systems in which relativistic and QED effects are not negligible into ab initio computational tools, and of extracting from the Dirac relativistic electron theory more nearly correct physical pictures.

*Ab initio Monte Carlo/molecular dynamics studies of structure and dynamics of polyatomic systems and solid/liquid interface*: The major difficulty in computer simulations of the structure and dynamics of metal, semiconductor and molecular clusters is the description of the many-body interactions. The pair-wise approximation commonly used to describe these systems does not work well for covalent and metallic systems where many-body interactions play a crucial role. We have developed ab initio molecular dynamics and replica Monte Carlo algorithms that describe the many-body interactions in these clusters in terms of *ab initio* correlated method.

**Selected peer-reviewed publications (2009 – 2011)**

- Spinel LiMn
_{2-x}Ni_{x}O_{4}cathode materials for high energy density lithium ion rechargeable batteries, R. Singhal, José J. Saavedra, Rajesh Katiyar, Yasuyuki Ishikawa, Marius J. Vilkas, S. R. Das, M. S. Tomar and R. S. Katiyar, Journal of Renewable and Sustainable Energy, 1 (2009) 023102. - A Density-functional Theory Study of the Water-gas Shift Mechanism on Pt/Ceria (111), R. T. Kinch, C. R. Cabrera, Y. Ishikawa, J. Phys. Chem. C, 113 (2009) 9239.
- Density-Functional Theory Study of Interactions between Water and Carbon Monoxide Adsorbed on Platinum under Electrochemical Conditions, J. A. Santana and Y. Ishikawa, Chem. Phys. Letters, 478 (2009) 110
- Benchmarking atomic data for astrophysics: Fe XVII EUV lines, G. Del Zanna andY. Ishikawa, Astronomy and Astrophysics, 508 (2009) 1517.
- Separation of CO
_{2}from Light Gas Mixtures using Silicoaluminophosphates Nanoporous Sorbents: Effect of Multiple Step Ion Exchange and Adsorption Mechanism via Computational Studies, Ana G. Arévalo-Hidalgo, Juan A. Santana, Rqiang Fu, Yasuyuki Ishikawa and Arturo J. Hernández-Maldonado, Microporous & Mesoporous Materials, 130 (2010) 142. - Relativistic multireference many-body perturbation theory for open-shell ions with multiple valence shell electrons: the transition rates and lifetimes of the excited levels in chlorinelike Fe X, Yasuyuki Ishikawa, Juan A. Santana, Elmar Traebert, J. Phy. B (Special issue on High Precision Atomic Physics) 43 (2010) 074022.
- Relativistic R-matrix close-coupling method based on the effective many-body Hamiltonian: Electron-impact excitation of electric dipole-allowed and spin-forbidden transitions of the S
^{4+}ion, J. A. Santana and Y. Ishikawa, J. Phys. B (Special issue on High Precision Atomic Physics) 43 (2010) 074030. - Electrochemical hydrogen oxidation on Pt(110): A combined direct MD/DFT study, J. A. Santana, J. J.Mateo,Y. Ishikawa, J. Phys. Chem. C 114 (2010) 4995
- A density-functional theory study of electrochemical absorption of sulfuric acid anions on Pt(111), Juan A. Santana, Carlos R. Cabrera, Yasuyuki Ishikawa, Phys. Chem. Chem. Phys. 12 (2010) 9526.
- In Search of Active Site in Nitrogen-doped Carbon Nanotube Electrodes for Oxygen Reduction Reaction, Chitturi Venkateswara Rao, Carlos R. Cabrera and Yasuyuki Ishikawa, J. Phys. Chem. Letters, 1 (2010) 2622
- Interactions between water and carbon monoxide adsorbed on Pt and Pt-Ru alloy surfaces under electrochemical conditions: density-functional theory study, J. A. Santana and Y. Ishikawa, Electrochimica Acta, 56 (2010) 945.
- EUV spectra of highly charged Pt ions with several valence-shell electrons: Observation and accurate calculations, E. Traebert, J. Clementson, P. Beiersdorfer, J. A. Santana, and Y. Ishikawa, Physical Review A 82 (2010) 062519.
- Synthesis and electrocatalytic oxygen reduction activity of graphene-supported Pt
_{3}Co and Pt_{3}Cr alloy nanoparticles, Chitturi Venkateswara Rao, Arava Leela Mohana Reddy, Yasuyuki Ishikawa and Pulickel M. Ajayan, Carbon 49 (2011) 931 - Relativistic R-matrix close-coupling method based on the effective many-body Hamiltonian: electron-impact excitation of the 3s
^{2}^{1}S – 3s3p^{1}P^{o}_{J }electric dipole-allowed transition of the Ar^{6+}ion, J. Santana and Y. Ishikawa, Can. J. Phys. (Proceedings of ASOS10 invited talks), in press (2011).