About Me

Education

• B.Sc. St. Xavier’s College, Mumbai, 1997
• M.Sc. University of Pune, Pune, 1999
• Ph.D. University of Florida, Gainesville, 2006

Employment

• Manager of Research Computing, Lehigh University (09/2014-present)
• HPC User Services Consultant, Louisiana State University (08/2010-09/2014)
• Postdoctoral Fellow, Indiana University (10/2006-08/2010)
• Graduate Research & Teaching Assistant, University of Florida (08/1999-09/2006)

Research Interest

• Ab-Initio Molecular Dynamics
• Wavepacket Dynamics
• Spectroscopy
• Theoretical Method Development
• Scientific Computing

Publications

• J. Li, A. B. Pacheco, K. Raghavacharia and S. S. Iyengar, “A Grotthuss-like proton shuttle in the anomalous C2H3+ carbocation: energetic and vibrational properties for isotopologues”, Phys. Chem. Chem. Phys., 18, 29395 (2016).
• A. B. Pacheco, S. M. Dietrick, P. S. Stevens and S. S. Iyengar, “Pump-probe atom-centered density matrix propagation studies to gauge anharmonicity and energy repartitioning in atmospheric reactive adducts: Case study of OH + Isoporene and OH + Butadiene reaction intermediates”, J. Phys. Chem. A 116, 4108 (2012).
• S. M. Dietrick, A. B. Pacheco, P. S. Stevens and S. S. Iyengar, “The influence of water on anharmonicity, stability and vibrational energy distribution of hydrogen-bonded adducts in atmospheric reactions: Case study of the OH + Isoprene reaction intermediate using ab-initio Molecular Dynamics”, J. Phys. Chem. A 116, 399 (2012).
• A. B. Pacheco and S. S. Iyengar, “Multi-Stage Ab-initio Quantum Wavepacket Dynamics for Electronic Structure and Dynamics in open systems: Momentum Representation, Coupled Electron Nuclear dynamics and External Fields”, J. Chem. Phys. 134, 074107 (2011).
• A. B. Pacheco and S. S. Iyengar, “A Multi-Stage Ab-initio Quantum Wavepacket Dynamics Formalism for Electronic Structure and Dynamics in Open Systems”, J. Chem. Phys. 133, 044105 (2010).
• D. Vimal, A. B. Pacheco, S. S. Iyengar and P. S. Stevens, “Experimental and theoretical study of the kinetics of the OH + 1,3-butadiene reaction between 263 and 423 K at low pressure”, J. Phys. Chem. A 112, 7227 (2008).
• A. B. Pacheco, B. Thorndyke, A. Reyes, and D. A. Micha, “Quantum dynamics of an excited alkali atom in a noble gas cluster: Lithium attached to a helium cluster”, J. Chem. Phys. 127, 244504 (2007)
• A. B. Pacheco, A. Reyes, and D. A. Micha, “First principles dynamics treatment of light emission in alkali atom-noble gas atom collisions around 10 keV”, Phys. Rev. A 74, 062714 (2006)
• A. B. Pacheco, A. Reyes, and D. A. Micha, “Light absorption during alkali atom-noble gas atom interactions at thermal energies: A quantum dynamics treatment”, J. Chem. Phys. 125, 154313 (2006)
• First Principles Dynamics of Transient Light Absorption and Emission of Alkali Atoms Interacting with Rare Gas Atoms, Ph. D. Thesis, University of Florida (2006). (PDF)

Conference Presentations

Posters

• A. B. Pacheco and S. S. Iyengar, A Multi-Stage Ab-initio Quantum Wavepacket Dynamics Formalism for Electronic Structure and Dynamics in Open Systems. 42nd MidWest Theoretical Chemistry Conference, West Lafayette, IN (2010). (Abstract) (Poster)
• A. B. Pacheco and S. S. Iyengar, Quantum Wavepacket Ab-initio Molecular Dynamics Formalism for Calculating Electron Transport in Molecular Wires. American Conference on Theoretical Chemistry Conference, Evanston, IL. (2008). (Abstract) (Poster)
• S. M. Dietric, A. B. Pacheco and S. S. Iyengar, Study of the reactivity of OH radical adducts with isoprene in gas phase and adsorbed on an aerosol using Ab-Initio Molecular Dynamics. American Conference on Theoretical Chemistry Conference, Evanston, IL. (2008). (Abstract) (Poster)
• A. B. Pacheco and S. S. Iyengar, Quantum Wavepacket Ab-initio Molecular Dynamics Formalism for Calculating Electron Transport in Molecular Wires. 40th MidWest Theoretical Chemistry Conference, Ann Arbor, MI. (2008). (Abstract) (Poster)
• S. M. Dietric, A. B. Pacheco and S. S. Iyengar, Study of the reactivity of OH radical adducts with isoprene in gas phase and adsorbed on an aerosol using Ab-Initio Molecular Dynamics. 40th MidWest Theoretical Chemistry Conference, Ann Arbor, MI. (2008). (Abstract) (Poster)
• A. B. Pacheco and S. S. Iyengar, Quantum Wavepacket Ab-initio Molecular Dynamics Formalism for Calculating Electron Transport in Molecular Wires. 39th MidWest Theoretical Chemistry Conference, Bloomington, IN. (2007). (Abstract) (Poster)
• A. B. Pacheco and D. A. Micha, Light Emission during Interactions of an Excited Alkali Atom inside or at the surface of a Noble Gas Atom Cluster: A Density Matrix Treatment. 46th Sanibel Symposium, St. Simon’s Island, GA. (2006). (Abstract) (Poster)
• A. B. Pacheco and D. A. Micha, Calculation of Light Absorption Intensities during Alkali Atom - Noble Gas Atom Interactions from a First Principles Dynamics. 45th Sanibel Symposium, St. Simon’s Island, GA. (2005). (Abstract) (Poster)
• A. B. Pacheco and D. A. Micha, Dynamics of Light Emission during Alkali Atom - Rare Gas Atom Interactions: From Atom-Atom Collisions to Interactions in Clusters. 44th Sanibel Symposium, St. Augustine, FL. (2004). (Abstract) (Poster)
• A. Reyes, D. A. Micha and A. Pacheco, First Principles Quantum Dynamics of Electronic Excitation and Spin-Orbit Recoupling in Alkali-Noble Gas Atom Interactions. 43rd Sanibel Symposium, St. Augustine, FL. (2003).
• A. B. Pacheco and D. A. Micha, Electronic State-to-State Collision Cross Sections using Transition Integrals. 42nd Sanibel Symposium, St. Augustine, FL. (2002). (Abstract) (Poster)

Oral and Contributed Talks

• A. B. Pacheco, A Multi-Stage Ab-initio Wavepacket Dynamics Formalism for Electronic Structure and Dynamics in Open Systems. Center for Computation and Technology, Louisiana State University, Baton Rouge, LA, June 10 (2010). (Abstract) (Slides)
• A. B. Pacheco and S. S. Iyengar, A Multi-Stage Ab-initio Wavepacket Dynamics Formalism for Electron Dynamics in Open Systems. 41st MidWest Theoretical Chemistry Conference. Carbondale, IL. (2009).</span> (Abstract) (Slides)
• D. A. Micha, A. Leathers, A. Pacheco, A. Sudhyadhom and B. R. Thorndyke. Dissipative Femtosecond Dynamics of Electronically Excited Systems: A Density Matrix Approach. Amer. Chem. Soc. National Meeting, Atlanta, Ga. (2006).
• D. A. Micha, A. Reyes, A. Pacheco and B. Thorndyke, Time-Propagation of the Quantum-Classical Density Matrix for Electronically Excited Molecular Systems. Amer. Chem. Soc. National Meeting, Anaheim, Ca. (2004).
• A. Reyes, D. A. Micha and A. Pacheco, Electronic Excitation and Spin-Orbit Recoupling Cross Sections for Alkali-Atom/Noble Gas-Atom Collisions from a First Principles Quantum Dynamics. Amer. Phys. Soc. DAMOP Meeting, Boulder, Co. (2003).