@article{sremaniak_whitten_2008, title={Theoretical treatment of excited electronic states of adsorbates on metals: Electron attachment to CO2 adsorbed on K-modified Pt(111)}, volume={602}, ISSN={["1879-2758"]}, DOI={10.1016/j.susc.2007.11.029}, abstractNote={Abstract Theoretical studies of photoinduced processes involving electron attachment to CO 2 adsorbed on Pt(1 1 1) in the presence of a coadsorbed K atom are reported. First principles theoretical methods suitable for describing electronic states embedded in a near continuum of metal to metal excitations are described. Wave functions are constructed by ab initio configuration interaction methods which allow a rigorous resolution of states and differentiation between competing pathways of molecular desorption and dissociation. An embedding theory is used to achieve high accuracy in the adsorbate-surface region. Compared to CO 2 adsorbed on Pt(1 1 1), the K promoter lowers the work function of the system from 5.6 to 5.2 eV and decreases the energy required to form the electron attached excited electronic state from 6.8 to 5.6 eV. However, stabilization of CO 2 depends strongly on orientation and proximity to the K adatom. The most favorable pathway leading to dissociation requires that CO 2 be adsorbed at a site that does not share Pt atoms with the K adsorption site, i.e., at next-nearest neighbor sites. As was found for Pt(1 1 1) without a K adatom, the dissociation pathway involves bending of CO 2 in the excited state followed by possible dissociation on the excited state surface where the barrier height is reduced from its value of 1.0 eV on the Pt surface to 0.34 eV. As is the case for the unmodified surface, dissociation could also occur after return to the ground state potential energy surface via vibrational processes.}, number={4}, journal={SURFACE SCIENCE}, author={Sremaniak, Laura S. and Whitten, Jerry L.}, year={2008}, month={Feb}, pages={834–842} }
 @article{sremaniak_whitten_2007, title={Theoretical treatment of excited electronic states of adsorbates on metals: Electron attachment to CO2 adsorbed on Pt(111)}, volume={601}, ISSN={["0039-6028"]}, DOI={10.1016/j.susc.2007.04.118}, abstractNote={Photochemistry involving adsorbates on metals often proceeds by photoexcitation of the metal followed by transient attachment of photoemitted electrons to the adsorbate. First principles theoretical methods suitable for describing electronic states embedded in a near continuum of metal to metal excitations are described and an application to electron attachment to CO2 adsorbed on Pt(1 1 1) is reported. Wavefunctions are constructed by ab initio configuration interaction methods which allow a rigorous resolution of states and differentiation between competing pathways of molecular desorption and dissociation. An embedding theory is used to achieve high accuracy in the adsorbate-surface region. The energy required to form the electron attached state is 5.2 eV for excitation to bent CO2 and 6.8 eV for excitation to linear CO2, hence both energies are near the work function of the metal (5.7 eV). The process also involves localization of the metal hole and attraction of the charged adsorbate to the metal. Optimum geometries are calculated and pathways that results in desorption, dissociation by bond rupture directly in the excited electronic state, or dissociation after return to the ground state potential energy surface via vibrational processes are explored.}, number={18}, journal={SURFACE SCIENCE}, author={Sremaniak, Laura S. and Whitten, Jerry L.}, year={2007}, month={Sep}, pages={3755–3759} }
 @article{qin_sremaniak_whitten_2006, title={CO adsorption on Ag(100) and Ag/MgO(100)}, volume={110}, ISSN={["1520-6106"]}, DOI={10.1021/jp0575207}, abstractNote={Theoretical studies of CO adsorption on a two-layer Ag(100) film and on a two-layer Ag film on a MgO(100) support are reported. Ab initio calculations are carried at the configuration interaction level of theory using embedding methods to treat the metal-adsorbate region and the extended ionic solid. The metal overlayer is considered in two different structures: where Ag-Ag distances are equal to the value in the bulk solid, and for a slightly expanded lattice in which the Ag-Ag distances are equal to the O-O distance on the MgO(100) surface. The calculated adsorption energy of Ag(100) on MgO(100) is 0.58 eV per Ag interfacial atom; the Ag-O distance is 2.28 A. A small transfer of electrons from MgO to Ag occurs on deposition of the silver overlayer. CO adsorption at an atop Ag site is found to be the most stable for adsorption on the two-layer Ag film and also for adsorption on Ag deposited on the oxide; CO adsorption energies range from 0.12 to 0.19 eV. The CO adsorption energy is reduced for the Ag/MgO system compared to adsorption on the unsupported metal film thereby providing evidence for a direct electronic effect of the oxide support at the metal overlayer surface. Expansion of the Ag-Ag distance in the two-layer system also reduces the adsorption energy.}, number={23}, journal={JOURNAL OF PHYSICAL CHEMISTRY B}, author={Qin, Changyong and Sremaniak, Laura S. and Whitten, Jerry L.}, year={2006}, month={Jun}, pages={11272–11276} }
 @article{sremaniak_whitten_truitt_white_2006, title={Weak hydrogen bonding can initiate alkane C-H bond activation in acidic zeolites}, volume={110}, ISSN={["1520-6106"]}, DOI={10.1021/jp0658703}, abstractNote={Ab initio calculations at the Hartree-Fock self-consistent field/single determinant (SCF) and configuration interaction multi-determinant (CI) expansion levels have been used to show that isobutane primary C-H bond activation occurs via direct protium exchange with the zeolite surface via a weakly hydrogen-bonded complex. The calculated 15 kcal/mol activation barrier agrees with the 13.7 kcal/mol value from a recently reported experimental study (J. Am. Chem. Soc. 2006, 128, 1847-1852). Overall, the mechanism described in this contribution demonstrates that weak C-H to O hydrogen bonding leads to complexes at the zeolite acid site that can facilitate C-H bond activation.}, number={42}, journal={JOURNAL OF PHYSICAL CHEMISTRY B}, author={Sremaniak, Laura S. and Whitten, Jerry L. and Truitt, Matthew J. and White, Jeffery L.}, year={2006}, month={Oct}, pages={20762–20764} }
 @article{mowrer_lucovsky_sremaniak_whitten_2004, title={Ab initio theory calculations of the electronic structure of nc-AS(2)S(3) and GeS2: an intrinsic mechanism for reversible photo-darkening}, volume={338-40}, DOI={10.1016/j.jnocrysol.2004.03.038}, number={Jun 15 2004}, journal={Journal of Non-crystalline Solids}, author={Mowrer, T. and Lucovsky, G. and Sremaniak, L. S. and Whitten, Jerry}, year={2004}, pages={543–547} }
 @article{lucovsky_mowrer_sremaniak_whitten_2004, title={Local atomic structure and infrared effective charges in tetrahedrally-bonded glasses from ab initio theory electronic structure calculations}, volume={338}, ISSN={["0022-3093"]}, DOI={10.1016/j.jnoncrysol.2004.02.043}, abstractNote={Ab initio calculations are applied to small clusters containing the elements of short range order determined from X-ray and electron diffraction radial distributions for tetrahedrally-bonded, continuous random networks glasses including SiO2, GeO2, BeF2, and GeS2. The calculations have been used to determine the dependence of the total energy on the bond-angle at the two-fold coordinated O-, F-, and S-atom sites, and the infrared effective charges for normal mode infrared active network vibrations. The results of these calculations are in excellent agreement with experiment. Of particular significance are the calculated bond angle distributions for SiO2 and GeO2, which are significantly narrower than previously assumed, but in good agreement with recent modeling and experimental studies.}, number={Jun 15 2004}, journal={JOURNAL OF NON-CRYSTALLINE SOLIDS}, author={Lucovsky, G and Mowrer, T and Sremaniak, LS and Whitten, JL}, year={2004}, month={Jun}, pages={155–158} }
 @article{lucovsky_sremaniak_mowrer_whitten_2003, title={A  new approach for calculating the electronic structure and vibrational properties of non-crystalline solids: Effective charges for infrared-active normal mode vibrations in oxide and chalcogenide materials}, volume={326}, number={2003 Oct 1}, journal={Journal of Non-crystalline Solids}, author={Lucovsky, G. and Sremaniak, L. S. and Mowrer, T. and Whitten, J. L.}, year={2003}, pages={14-} }