UT Chem/Biochem Dept

The 2008-2009 Beckman Scholars: Devin A. Matthews, PhD

Faculty Mentor: Professor John F. Stanton Length of term: Summer 08, Fall 08, Spring 09, Summer 09 Honors & Awards:University Honors (Fall 06, Spring 07, Fall 07, Spring 09); Dedman Merit Scholarship (2006); Robert C. Byrd Scholarship (2006); Thomas and Elizabeth Merner Scholarship (2007); Dorothy B. Banks Charitable Trust Scholarship (2007); Charles Morton Share Trust Scholarship (2007-9); Jean Dreyfus Boissevain Undergraduate Scholarship (2007); Georgia Felter and Carey Legett, Jr., Dean's Endowed Scholarship (2008); Lockheed Martin Award for Excellence in Chemistry Research (2008); Robert Smith and Lyall Pickett Davis Scholarship (2009); Dean's Honored Graduate (2010); DOE Computation Science Graduate Fellowship (2010-2) Publications: Calculated stretching overtone levels and Darling-Dennison resonances in water: A triumph of simple theoretical approaches, D. A. Matthews, J. V‡zquez and J. F. Stanton, Mol. Phys., 2007, 105, 2659.; Calculation of vibrational transition frequencies and intensities in water dimer: Comparison of different vibrational approaches, H. G. Kjaergaard, A. L. Garden, G. M. Chaban, R. B. Gerber, D. A. Matthews and J. F. Stanton, J. Phys. Chem. A, 2008, 112, 4324.; Gas-phase infrared spectrum of methyl nitrate, J. F. Stanton, B. A. Flowers, D. A. Matthews, A. F. Ware and G. B. Ellison, J. Mol. Spect., 2008, 251, 384.; Quantitative analysis of Fermi resonances by harmonic derivatives of perturbation theory corrections, D. A. Matthews and J. F. Stanton, Mol. Phys., 2009, 107, 213. Where is he now? Graduated with Bachelor of Science in Chemistry with Honors, and Special Departmental Honors in Chemistry, May 2010. Graduated with PhD in Chemistry from UT Austin in August, 2014. Devin is currently a postdoc in the Department of Computer Science at UT Austin. How can I contact him?dmatthews at utexas.edu

Beckman research project in the Stanton group:

Download a copy of Devin's Research report, entitled An extension of the equation-of-motion coupled cluster method to biradicals with full and approximate triple excitations

The equation-of-motion coupled cluster (EOM-CC) method,^1,2 is a powerful theoretical tool for the treatment of molecules with unpaired electrons, known as radicals. This approach, which exploits the structure of Fock space (the space spanned by all SCF determinants for all numbers of electrons), is based on the calculation of a "well-behaved" N-electron (closed shell) reference state. This information is then used to affect a similarity transformation of the electronic Hamiltonian and diagonalize the transformed Hamiltonian. When the Hamiltonian is diagonalized in the N-electron space, the method gives the excitation spectrum of the molecule of interest. Diagonalization in other sectors of Fock space (a different number of electrons) gives energies of specific target states. For instance, diagonalization in the (N-1)-electron space gives doublet radicals (one unpaired spin). The advantages of these approaches include rigorous spin-adaptation, balance in the treatment of different electron configurations, and ease of application.

The usual (N-1)-electron version of EOM-CC is to be extended to the singles, doubles and triples truncation of the CC equations (EOM-CCSDT). This will allow for a more accurate treatment of doublet radicals than is currently available with EOM-CCSD.² Perhaps more importantly, this method is also to be extended to utilize (N-2)-electron target states which will provide a useful technique for the study of so-called biradicals, which are ubiquitous in the chemistry of reactive intermediates found in processes such as combustion and the chemistries of the atmosphere and interstellar space.^3-6