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# Louis J. Massa, Ph.D.

Professor - Quantum Crystallography

### Contact Information:

office 1300N (tel 212-772-4016), lab 1300N (tel 212-772-4311), fax (dept) 212-772-5332, email LMassa@Hunter.CUNY.edu,

### Education:

B.S. Lemoyne College, Physics, M.S. Clarkson University, Physics, Ph.D. Georgetown University, Physics, Postdoc, Brookhaven National Laboratory

### Research Summary:

Quantum Crystallography (QCr) refers to the combination of structural crystallographic information with quantum-mechanical theory. The objective is to facilitate computational chemistry calculations and thereby enhance the information that may be derived from a crystallographic experiment. This concept has a long history and in recent years has been finding increased attention because of the advances in both theory and computers. Our method for obtaining quantum mechanical molecular energy involves the use of parts of a whole molecule, which in our formalism are called kernels. The individual calculations based on kernels are relatively small, compared to that which would be required to treat an entire molecule all at once. Subsequently, we sum kernel contributions to obtain the energy for a whole molecule. In so doing we simplify the formidable task of obtaining a true quantum energy calculation for very large molecules. The saving of computational time is significant. The theoretical background for our approach to quantum crystallography may be found in References and additional references therein.

### Selected Publications

Proposed New Materials: Boron Fullerenes, Nanotubes, and Nanotori, V. Dadashev, A.Gindulyte, W.N. Lipscomb, L. Massa, and R. Squire, Structures and Mechanisms: From Ashes to Enzymes, Gareth R. Eaton, Don C. Wiley, and Oleg Jardetzky, eds., ACS Symposium Series Volume 827, Oxford University Press, 2002.

Form Factors For Core Electrons Useful In The Quantum Crystallography (QCr) Of Organic Molecules, Lulu Huang, Lou Massa, and Jerome Karle, Acta Cryst , (2002) A58, 410-411.

Quantal Density Functional Theory of Excited States: The State Arbitrariness of the Model Noninteracting System, M. Slamet, R. Singh, L. Massa, and V. Sahni, Phys. Rev. A 66, , 042504 (2003).

Determination of a wave function functional, X.-Y. Pan, V. Sahni, and L. Massa Phys. Rev. Lett. 93, 130401 (2004).