Our research deals with theoretical and computational aspects of molecular and materials sciences with particular emphasis on ab-initio and DFT calculations, quantum molecular dynamics, density matrix theory, and classical molecular dynamics. It includes photoinduced phenomena in the gas phase, clusters, and at solid or metallic surfaces. We use quantum and statistical mechanics, mathematical, and computational methods to describe time-dependent phenomena such as femtosecond dynamics, photochemistry, and quantum control in both simple and complex molecular systems.

We are particularly interested in the interaction between an adsorbed molecule and a substrate when irradiated with a femtosecond light pulse and its description within a time-dependent quantum mechanical framework. Many questions arise during this chemical process: How much energy gets transferred to the substrate or the adsorbate? Does the adsorbate get vibrationally or rotationally excited? How much energy gets dissipated and how long does it take? Does the adsorbate react with other adsorbate atoms or molecules? Does the energy eventually equilibrate to the surface temperature or does it escape from the surface prior to equilibration? Questions such as these have important implications in processes ranging from the heating of a space vehicle on reentry into the atmosphere, to the precision etching of metallic features during integrated circuit fabrication, to the control of reaction pathways in heterogeneous catalysis. The combination of technological implication and richness in behavior has provided the motivation for an increasing effort toward achieving an atomic-level understanding of elementary dynamical processes at metal surfaces.

Representative Publications:

A. Cruz, E. Ramírez, A. Santana, B. Barletta, G.E. López, “Molecular dynamic study of subtilisin Carlsberg in aqueous and nonaqueous solvents”, Molecular Simulation, 2009, 35(3), 205-212.

E. Ramírez, A. Cruz, D. Rodríguez, L. Uchima, R. Pietri, A. Santana, J. López Garriga, G. E. López, "Effects of active site mutations in haemoglobin I Lucina pectinata: a molecular dynamic study”, Molecular Simulations, 2008, 34(7), 715-725.

E. Ramirez, A. Santana, A. Cruz, and G.E. López, "Liquid-liquid equilibrium in model surfactant", J. Chem. Phys., 2007, 127, 224705.

E. Ramírez , A. Santana, A. Cruz , I. Plasencia and G. E. López, Molecular Dynamics of Surfactant Protein C: From Single Molecule to Heptameric Aggregates, Biophysical Journal, 2006, 90:2698-2705.

R. Nieto, A. Santana, S.P. Hernandez-Rivera, R.T. Lareau, R.T. Chamberlain, and M.E. Castro-Rosario, "Quantum dots for detection of trace amount of nonvolatile explosives: the effect of TNT in the fluorescence of CdSe quantum dots?, in Sensors, and Command, Control, Communications, and Intelligence (C3I) Technologies for Homeland Security and Homeland Defense III; Edward M. Carapezza; Ed., Proc. SPIE, 5403: 256-260, 2004.

S. Nieto, L.M. Gomez, A. Santana, J.G. Briano, N. Mina, S.P. Hernandez-Rivera, and M.E. Castro, "The chemistry of TNT on clean and hydroxyl-precovered Ottawa sand particles?, in Detection and Remediation Technologies for Mines and Minelike Targets IX, Russell S. Harmon, J. Thomas Broach, John H. Holloway, Jr., Eds., Proc. SPIE, 5415: 1400-1407, 2004.

L.M. Gomez, A. Santana, S.P. Hernandez-Rivera, and M.E. Castro, "Imaging and characterization of aerosol-deposited TNT nanoparticles: a near-field optical microscopy study?, in Detection and Remediation Technologies for Mines and Minelike Targets IX, Russell S. Harmon, J. Thomas Broach, John H. Holloway, Jr., Eds., Proc. SPIE, 5415: 468-473, 2004.

L.M. Gomez, A. Santana, N. Mina, S.P. Hernández-Rivera, M.E. Castro, "Femtosecond laser UVphotochemistry of TNT deposits: the role of hydroxyls?, in Detection and Remediation Technologies for Mines and Minelike Targets IX, Russell S. Harmon, J. Thomas Broach, John H. Holloway, Jr., Eds., Proc. SPIE, 5415: 486-493, 2004.

L.F. Alzate, Y.M. Colon, C.M. Ramos, A. Santana, S.P. Hernandez-Rivera, M.E. Castro, J.G. Briano, and N. Mina, "Density-functional-theory calculations of TNT and its interaction with siloxane sites of clay minerals?, in Detection and Remediation Technologies for Mines and Minelike Targets IX, Russell S. Harmon, J. Thomas Broach, John H. Holloway, Jr., Eds., Proc. SPIE, 5415: 1367-1376, 2004.

Y.M. Colon, L.F. Alzate, C.M. Ramos, A. Santana, S.P. Hernandez-Rivera, M.E. Castro, M. Munoz, and N. Mina, "Adsorption of RDX on clay?, in Detection and Remediation Technologies for Mines and Minelike Targets IX, Russell S. Harmon, J. Thomas Broach, John H. Holloway, Jr., Eds., Proc. SPIE, 5415: 1419-1430, 2004.