Zhiyong Zhang

All Publications

• Theoretical study of CDW phases for bulk NbX2 (X = S and Se). Physical chemistry chemical physics : PCCP Du, H., Jiang, Z., Zheng, J., Zhang, X., Wang, W., Zhang, Z. 2024

  Abstract

  In most two-dimensional transition metal chalcogenides, the superconducting phase coexists with the charge density wave (CDW) phase. There exists at least one case, i.e. bulk 2H-NbS2, that does not conform to this picture. Scientists have shown great interest in trying to experimentally find the CDW phase of bulk NbS2 since 1975. Is there any theoretically more stable thermodynamic state than its higher-temperature metal phase, especially in the case of charge injection? Theoretically more stable CDW bulk configurations (TC for 2H-NbS2 and TTs for 2H-NbSe2) with partial pseudo energy gaps were predicted through the harmonic phonon softening theory and first-principles calculations. The ratios of larger to smaller pseudo gaps around K-H segment in the Brillouin zone for CDW phases are basically equal to those of superconductivity phases for bulk 2H-NbX2 (X = S and Se). The CDW phase should coexist with its superconductor state below the critical temperature rather than the metal phase for bulk 2H-NbS2. The presence of CDW phase should be more easily observed experimentally when the injected charge reaches 0.5e/Nb18S36 for bulk 2H-NbS2. Our calculations of density of state (DOS) indicated that, during Nb atoms contracting to form the CDW phases with symmetry breaking in the in-plane direction, dominant conductive carriers are always of p-type for bulk 2H-NbS2 while the alternation of carrier type from p-type to n-type occurs for bulk 2H-NbSe2. The Fermi level continuously drops and then the M-L segment of the out-of-plane energy band emerges from the Fermi surface, which corresponds to the reversal of p-n type sign. Lifshitz transition of pocket-vanishing types occurs in the out-of-plane direction without symmetry breaking during the geometrical structural phase transition for bulk 2H-NbSe2. Our calculations have theoretically addressed the long-standing coexistence issue of CDW and superconducting phases.

  View details for DOI 10.1039/d3cp04426b

  View details for PubMedID 38167696

• Design Principles for Rotational Cluster Anion [BH4](-) Promote Superionic Conductivity in Sodium-Rich Antiperovskite Na3OBH4 JOURNAL OF PHYSICAL CHEMISTRY C Zhao, Q., Guo, J., Su, M., Suo, B., Zhu, H., Zhou, B., Zhang, Z., Song, Q. 2022

  View details for DOI 10.1021/acs.jpcc.2c05262

  View details for Web of Science ID 000859284900001

• Theoretical study of the synthesis, characterization and hydrogen storage properties of a high-density hydrogen storage material: (CH3NH3)BH4 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY Zhao, Q., Chen, L., Suo, B., Zhang, Z., Deng, D., Zhou, B., Zhu, H., Song, Q. 2021; 46 (37): 19498-19507

  View details for DOI 10.1016/j.ijhydene.2021.03.088

  View details for Web of Science ID 000653102200009

• --Peroxo Species Formed in the Bulk of Silicate Cathodes. Angewandte Chemie (International ed. in English) Chen, Z., Schwarz, B., Zhang, X., Du, W., Zheng, L., Tian, A., Zhang, Y., Zhang, Z., Zeng, X. C., Zhang, Z., Huai, L., Wu, J., Ehrenberg, H., Wang, D., Li, J. 2021

  Abstract

  Oxygen redox in Li-rich oxides may boost the energy-density of lithium-ion batteries by incorporating oxygen chemistry in solid cathodes. However, oxygen redox in the bulk usually entangles with voltage hysteresis and oxygen release, resulting in a prolonged controversy in literature on oxygen transformation. Here, we report spectroscopic evidence of peroxo species formed and confined in silicate cathodes amid oxygen redox at high-voltage, accompanied with Co 2+ /Co 3+ redox dominant at low-voltage. First-principles calculations reveal that localized electrons on dangling oxygen drive the O-O dimerization. The covalence between the binding cation and the O-O dimer determines the degree of electron transfer in oxygen transformation. Dimerization induces irreversible structural distortion and slow kinetics. But peroxo formation can minimize the voltage drop and volume expansion in cumulative cationic and anionic redox. These findings offer insights into oxygen redox in the bulk for rational designs of high energy-density cathodes.

  View details for DOI 10.1002/anie.202100730

  View details for PubMedID 33624367

• Tuning conduction mechanism via surface termination and point defects in n-type LaAlO3/SrTiO3 interfaces Guan, L., Tan, F., Liang, Y., Xu, X., Han, S., Guo, J., Wang, J., Zhang, Z., Li, X. ELSEVIER. 2021

  View details for DOI 10.1016/j.apsusc.2020.147745

  View details for Web of Science ID 000582373900073

• The mechanism of V-modification in Li2CoSiO4 cathode material for Li-ion batteries: A combined first-principles and experimental study ELECTROCHIMICA ACTA Huai, L., Du, W., Zhang, Z., Zhang, X., Zhang, Z., Chen, Z., Wu, J., Wang, D., Li, J. 2020; 353

  View details for DOI 10.1016/j.electacta.2020.136564

  View details for Web of Science ID 000552978500011

• Theoretical study on martensitic-type transformation path from rutile phase to alpha-PbO(2)phase of Ti2(O)* CHINESE PHYSICS B Wang, W., Jiang, Z., Lin, Y., Zheng, J., Zhang, Z. 2020; 29 (7)

  View details for DOI 10.1088/1674-1056/ab8abe

  View details for Web of Science ID 000551725100001

• NWChem: Past, present, and future. The Journal of chemical physics Aprà, E., Bylaska, E. J., de Jong, W. A., Govind, N., Kowalski, K., Straatsma, T. P., Valiev, M., van Dam, H. J., Alexeev, Y., Anchell, J., Anisimov, V., Aquino, F. W., Atta-Fynn, R., Autschbach, J., Bauman, N. P., Becca, J. C., Bernholdt, D. E., Bhaskaran-Nair, K., Bogatko, S., Borowski, P., Boschen, J., Brabec, J., Bruner, A., Cauët, E., Chen, Y., Chuev, G. N., Cramer, C. J., Daily, J., Deegan, M. J., Dunning, T. H., Dupuis, M., Dyall, K. G., Fann, G. I., Fischer, S. A., Fonari, A., Früchtl, H., Gagliardi, L., Garza, J., Gawande, N., Ghosh, S., Glaesemann, K., Götz, A. W., Hammond, J., Helms, V., Hermes, E. D., Hirao, K., Hirata, S., Jacquelin, M., Jensen, L., Johnson, B. G., Jónsson, H., Kendall, R. A., Klemm, M., Kobayashi, R., Konkov, V., Krishnamoorthy, S., Krishnan, M., Lin, Z., Lins, R. D., Littlefield, R. J., Logsdail, A. J., Lopata, K., Ma, W., Marenich, A. V., Martin Del Campo, J., Mejia-Rodriguez, D., Moore, J. E., Mullin, J. M., Nakajima, T., Nascimento, D. R., Nichols, J. A., Nichols, P. J., Nieplocha, J., Otero-de-la-Roza, A., Palmer, B., Panyala, A., Pirojsirikul, T., Peng, B., Peverati, R., Pittner, J., Pollack, L., Richard, R. M., Sadayappan, P., Schatz, G. C., Shelton, W. A., Silverstein, D. W., Smith, D. M., Soares, T. A., Song, D., Swart, M., Taylor, H. L., Thomas, G. S., Tipparaju, V., Truhlar, D. G., Tsemekhman, K., Van Voorhis, T., Vázquez-Mayagoitia, Á., Verma, P., Villa, O., Vishnu, A., Vogiatzis, K. D., Wang, D., Weare, J. H., Williamson, M. J., Windus, T. L., Woliński, K., Wong, A. T., Wu, Q., Yang, C., Yu, Q., Zacharias, M., Zhang, Z., Zhao, Y., Harrison, R. J. 2020; 152 (18): 184102

  Abstract

  Specialized computational chemistry packages have permanently reshaped the landscape of chemical and materials science by providing tools to support and guide experimental efforts and for the prediction of atomistic and electronic properties. In this regard, electronic structure packages have played a special role by using first-principle-driven methodologies to model complex chemical and materials processes. Over the past few decades, the rapid development of computing technologies and the tremendous increase in computational power have offered a unique chance to study complex transformations using sophisticated and predictive many-body techniques that describe correlated behavior of electrons in molecular and condensed phase systems at different levels of theory. In enabling these simulations, novel parallel algorithms have been able to take advantage of computational resources to address the polynomial scaling of electronic structure methods. In this paper, we briefly review the NWChem computational chemistry suite, including its history, design principles, parallel tools, current capabilities, outreach, and outlook.

  View details for DOI 10.1063/5.0004997

  View details for PubMedID 32414274

• The generality of the GUGA MRCI approach in COLUMBUS for treating complex quantum chemistry. The Journal of chemical physics Lischka, H., Shepard, R., Muller, T., Szalay, P. G., Pitzer, R. M., Aquino, A. J., Araujo do Nascimento, M. M., Barbatti, M., Belcher, L. T., Blaudeau, J., Borges, I. J., Brozell, S. R., Carter, E. A., Das, A., Gidofalvi, G., Gonzalez, L., Hase, W. L., Kedziora, G., Kertesz, M., Kossoski, F., Machado, F. B., Matsika, S., do Monte, S. A., Nachtigallova, D., Nieman, R., Oppel, M., Parish, C. A., Plasser, F., Spada, R. F., Stahlberg, E. A., Ventura, E., Yarkony, D. R., Zhang, Z. 2020; 152 (13): 134110

  Abstract

  The core part of the program system COLUMBUS allows highly efficient calculations using variational multireference (MR) methods in the framework of configuration interaction with single and double excitations (MR-CISD) and averaged quadratic coupled-cluster calculations (MR-AQCC), based on uncontracted sets of configurations and the graphical unitary group approach (GUGA). The availability of analytic MR-CISD and MR-AQCC energy gradients and analytic nonadiabatic couplings for MR-CISD enables exciting applications including, e.g., investigations of pi-conjugated biradicaloid compounds, calculations of multitudes of excited states, development of diabatization procedures, and furnishing the electronic structure information for on-the-fly surface nonadiabatic dynamics. With fully variational uncontracted spin-orbit MRCI, COLUMBUS provides a unique possibility of performing high-level calculations on compounds containing heavy atoms up to lanthanides and actinides. Crucial for carrying out all of these calculations effectively is the availability of an efficient parallel code for the CI step. Configuration spaces of several billion in size now can be treated quite routinely on standard parallel computer clusters. Emerging developments in COLUMBUS, including the all configuration mean energy multiconfiguration self-consistent field method and the graphically contracted function method, promise to allow practically unlimited configuration space dimensions. Spin density based on the GUGA approach, analytic spin-orbit energy gradients, possibilities for local electron correlation MR calculations, development of general interfaces for nonadiabatic dynamics, and MRCI linear vibronic coupling models conclude this overview.

  View details for DOI 10.1063/1.5144267

  View details for PubMedID 32268762

• Origin of the structural diversity of the alkaline metal borohydride MBH4 (M = Li, Na, K, Rb and Cs): Insights from first-principles calculations INTERNATIONAL JOURNAL OF HYDROGEN ENERGY Zhao, Q., Song, Q., Zhu, H., Zhang, Z., Jiang, Z., Zhou, B. 2020; 45 (16): 9946–58

  View details for DOI 10.1016/j.ijhydene.2020.02.015

  View details for Web of Science ID 000523719700062

• Effects of the Dopant Site on the Absorption Properties of CsPb1-xMxI2Br (M = Ge, Sn, Sr, and Cu): A First-Principles Investigation JOURNAL OF PHYSICAL CHEMISTRY C Liang, Y., Guan, L., Xu, X., Han, S., Guo, J., Wang, J., Chen, X., Zhang, Z., Li, X. 2020; 124 (11): 6028–37

  View details for DOI 10.1021/acs.jpcc.9b08246

  View details for Web of Science ID 000526396000016

• Theoretical study on transport-scheme conversion of g-C3N4/TiO2 heterojunctions by oxygen vacancies Applied Surface Science Yan, M. 2020; 531

  View details for DOI 10.1016/j.apsusc.2020.147318

• A first-principles simulation of the metal borohydride ammonia borane complex (LiBH4)(2)(NH3BH3) and the decomposition reaction pathway for hydrogen storage INTERNATIONAL JOURNAL OF HYDROGEN ENERGY Song, Q., Zhao, Q., Jiang, Z., Zhang, Z., Zhu, H. 2019; 44 (36): 20121–32

  View details for DOI 10.1016/j.ijhydene.2019.05.224

  View details for Web of Science ID 000478711300059

• Comparison of geometry models in the study of perovskite heterostructures APPLIED SURFACE SCIENCE Guan, L., Tan, F., Shen, G., Liang, Y., Xu, X., Guo, J., Wang, J., Zhang, Z., Li, X. 2019; 475: 185–90

  View details for DOI 10.1016/j.apsusc.2018.11.248

  View details for Web of Science ID 000458482100022

• Theoretical Studies of Photocatalytic Behaviors of Isoelectronic C/Si/Ge/Sn-doped TiO2: DFT+U Applied Surface Science Chang, J., Jiang, Z., Zhang, Z., Lin, Y., Tian, P., Zhou, B. 2019: 1304-1309
• Theoretical study of disorder-order transition of sodium borohydride COMPUTATIONAL MATERIALS SCIENCE Dong, Y., Jiang, Z., Zhang, X., Song, Q., Zhou, B., Zhang, Z. 2016; 124: 87-91

  View details for DOI 10.1016/j.commatsci.2016.07.016

  View details for Web of Science ID 000383827500011

• Formation of charge-transfer complexes significantly improves the performance of polymer solar cells based on PBDTTT-C-T: PC71BM PROGRESS IN PHOTOVOLTAICS Fu, G., Yang, S., Shi, J., Zhang, Z., Liu, B., Zhao, X., Li, G., Li, X. 2015; 23 (6): 783-792

  View details for DOI 10.1002/pip.2509

  View details for Web of Science ID 000353388800011

• Formation of charge transfer complexes significantly improves the electron transfer process of polymer solar cells ORGANIC ELECTRONICS Fu, G., Wang, T., Cai, J., Shi, J., Luo, Z., Li, G., Li, X., Zhang, Z., Yang, S. 2015; 18: 70-76

  View details for DOI 10.1016/j.orgel.2015.01.011

  View details for Web of Science ID 000349548400010

• Complexation of Curium(III) with DTPA at 10-70 degrees C: Comparison with Eu(III)-DTPA in Thermodynamics, Luminescence, and Coordination Modes INORGANIC CHEMISTRY Tian, G., Zhang, Z., Martin, L. R., Rao, L. 2015; 54 (4): 1232-1239

  Abstract

  Separation of trivalent actinides (An(III)) from trivalent lanthanides (Ln(III)) is a challenging task because of the nearly identical chemical properties of these groups. Diethylenetriaminepentaacetate (DTPA), a key reagent used in the TALSPEAK process that effectively separates An(III) from Ln(III), is believed to play a critical role in the An(III)/Ln(III) separation. However, the underlying principles for the separation based on the difference in the complexation of DTPA with An(III) and Ln(III) remain unclear. In this work, the complexation of DTPA with Cm(III) at 10-70 °C was investigated by spectrophotometry, luminescence spectroscopy, and microcalorimetry, in conjunction with computational methods. The binding strength, the enthalpy of complexation, the coordination modes, and the luminescence properties are compared between the Cm(III)-DTPA and Eu(III)-DTPA systems. The experimental and computational data demonstrated that the difference between Cm(III) and Eu(III) in the binding strength with DTPA can be attributed to the stronger covalence bonding between Cm(III) and the nitrogen donors of DTPA.

  View details for DOI 10.1021/ic5016934

  View details for Web of Science ID 000349656600014

  View details for PubMedID 25654313

• From Orientation Disordered to Ordered-An Ab Initio Simulation on Ammonia Borane Phase Transition Within van der Waals Corrections JOURNAL OF COMPUTATIONAL CHEMISTRY Song, Q., Jiang, Z., Zhang, Z., Hou, Y., Zhang, X. 2015; 36 (1): 22-32

  View details for DOI 10.1002/jcc.23762

  View details for Web of Science ID 000345510800003

• Electronic Spectrum of the UO and UO+ Molecules JOURNAL OF PHYSICAL CHEMISTRY A Tyagi, R., Zhang, Z., Pitzer, R. M. 2014; 118 (50): 11758-11767

  Abstract

  Electronic theory calculations are applied to the study of the UO molecule and the UO(+) ion. Relativistic effective core potentials are used along with the accompanying valence spin-orbit operators. Polarized double-ς and triple-ς basis sets are used. Molecular orbitals are obtained from state-averaged multiconfiguration self-consistent field calculations and then used in multireference spin-orbit configuration interaction calculations with a number of millions of terms. The ground state of UO has open shells of 5f(3)7s(1), angular momentum Ω = 4, and a spin-orbit-induced avoided crossing near the equilibrium internuclear distance. Many UO excited states are studied with rotational constants, intensities, and experimental comparisons. The ground state of UO(+) is of 5f(3) nature with Ω = 9/2. Many UO(+) excited states are also studied. The open-shell nature of both UO and UO(+) leads to many low-lying excited states.

  View details for DOI 10.1021/jp505722y

  View details for Web of Science ID 000346759100012

  View details for PubMedID 25325820

• Spin-orbit DFT with analytic gradients and applications to heavy element compounds THEORETICAL CHEMISTRY ACCOUNTS Zhang, Z. 2014; 133 (12)

  View details for DOI 10.1007/s00214-014-1588-0

  View details for Web of Science ID 000346738600001

• Correlation of intercalation potential with d-electron configurations for cathode compounds of lithium-ion batteries Phys. Chem. Chem. Phys Chen, Z., Zhang, C., Zhang, Z., Li, J. 2014; 16: 13255-13261

  View details for DOI 10.1039/C4CP00855C

• Formation of charge transfer complexes significantly improves the performance of polymer solar cells based on PBDTTT-C-T: PC71BM Prog. Photovolt: Res. Appl. Fu, G., Yang, S., Shi, J., Zhang, Z., Liu, B., Zhao, X., Li, G., Li, X. 2014

  View details for DOI 10.1002/pip.2509

• Exotic Topological Insulator States and Topological Phase Transitions in Sb2Se3-Bi2Se3 Heterostructures ACS NANO Zhang, Q., Zhang, Z., Zhu, Z., Schwingenschloegl, U., Cui, Y. 2012; 6 (3): 2345-2352

  Abstract

  Topological insulator is a new state of matter attracting tremendous interest due to its gapless linear dispersion and spin momentum locking topological states located near the surface. Heterostructures, which have traditionally been powerful in controlling the electronic properties of semiconductor devices, are interesting for topological insulators. Here, we studied the spatial distribution of the topological state in Sb(2)Se(3)-Bi(2)Se(3) heterostructures by first-principle simulation and discovered that an exotic topological state exists. Surprisingly, the state migrates from the nontrivial Bi(2)Se(3) into the trivial Sb(2)Se(3) region and spreads across the entire Sb(2)Se(3) slab, extending beyond the concept of "surface" state while preserving all of the topological surface state characteristics. This unusual topological state arises from the coupling between different materials and the modification of electronic structure near Fermi energy. Our study demonstrates that heterostructures can open up opportunities for controlling the real-space distribution of the topological state and inducing quantum phase transitions between topologically trivial and nontrivial states.

  View details for DOI 10.1021/nn2045328

  View details for Web of Science ID 000301945900048

  View details for PubMedID 22339126

• First principles investigation of electronic structure change and energy transfer by redox in inverse spinel cathodes LiNiVO4 and LiCoVO4 JOURNAL OF MATERIALS CHEMISTRY Chen, Z., Li, J., Zhang, Z. 2012; 22 (36): 18968-18974

  View details for DOI 10.1039/c2jm33026a

  View details for Web of Science ID 000307790300040

• Electrochemical quantum tunneling for electronic detection and characterization of biological toxins Conference on Micro- and Nanotechnology Sensors, Systems, and Applications IV Gupta, C., Walker, R. M., Gharpuray, R., Shulaker, M. M., Zhang, Z., Javanmard, M., Davis, R. W., Murmann, B., Howe, R. T. SPIE-INT SOC OPTICAL ENGINEERING. 2012

  View details for DOI 10.1117/12.920692

  View details for Web of Science ID 000306560400002

• Sequestering uranium from seawater: binding strength and modes of uranyl complexes with glutarimidedioxime DALTON TRANSACTIONS Tian, G., Teat, S. J., Zhang, Z., Rao, L. 2012; 41 (38): 11579-11586

  Abstract

  Glutarimidedioxime (H(2)A), a cyclic imide dioxime ligand that has implications in sequestering uranium from seawater, forms strong tridentate complexes with UO(2)(2+). The stability constants and the enthalpies of complexation for five U(VI) complexes were measured by potentiometry and microcalorimetry. The crystal structure of the 1 : 2 metal-ligand complex, UO(2)(HA)(2)·H(2)O, was determined. The re-arrangement of the protons of the oxime groups (-CH=N-OH) and the deprotonation of the imide group (-CH-NH-CH-) results in a conjugated system with delocalized electron density on the ligand (-O-N-C-N-C-N-O-) that coordinates to UO(2)(2+)via its equatorial plane.

  View details for DOI 10.1039/c2dt30978e

  View details for Web of Science ID 000308655800010

  View details for PubMedID 22801978

• Rational designs of crystal solid-solution materials for lithium-ion batteries PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS Luo, T., Zhang, C., Zhang, Z., Zhu, Y., Li, J. 2011; 248 (9): 2027-2031

  View details for DOI 10.1002/pssb.201147085

  View details for Web of Science ID 000295367500005

• Thermodynamic, Spectroscopic, and Computational Studies of Lanthanide Complexation with Diethylenetriaminepentaacetic Acid: Temperature Effect and Coordination Modes INORGANIC CHEMISTRY Tian, G., Martin, L. R., Zhang, Z., Rao, L. 2011; 50 (7): 3087-3096

  Abstract

  Stability constants of two DTPA (diethylenetriaminepentaacetic acid) complexes with lanthanides (ML(2-) and MHL(-), where M stands for Nd and Eu and L stands for diethylenetriaminepentaacetate) at 10, 25, 40, 55, and 70 °C were determined by potentiometry, absorption spectrophotometry, and luminescence spectroscopy. The enthalpies of complexation at 25 °C were determined by microcalorimetry. Thermodynamic data show that the complexation of Nd(3+) and Eu(3+) with DTPA is weakened at higher temperatures, a 10-fold decrease in the stability constants of ML(2-) and MHL(-) as the temperature is increased from 10 to 70 °C. The effect of temperature is consistent with the exothermic enthalpy of complexation directly measured by microcalorimetry. Results by luminescence spectroscopy and density functional theory (DFT) calculations suggest that DTPA is octa-dentate in both the EuL(2-) and EuHL(-) complexes and, for the first time, the coordination mode in the EuHL(-) complex was clarified by integration of the experimental data and DFT calculations. In the EuHL(-) complex, the Eu is coordinated by an octa-dentate H(DTPA) ligand and a water molecule, and the protonation occurs on the oxygen of a carboxylate group.

  View details for DOI 10.1021/ic200025s

  View details for Web of Science ID 000288730400051

  View details for PubMedID 21375350

• Dynamic Mechanisms for Ammonia Borane Thermolysis in Solvent: Deviation from Gas-Phase Minimum-Energy Pathways JOURNAL OF PHYSICAL CHEMISTRY LETTERS Zimmerman, P. M., Zhang, Z., Musgrave, C. B. 2011; 2 (4): 276-281

  View details for DOI 10.1021/jz101629d

  View details for Web of Science ID 000291500500002

• Multiple-exicton generation in quantum dots, an ab initio study ACS National Meeting ZHANG, Z. 2011
• Simultaneous Two-Hydrogen Transfer as a Mechanism for Efficient CO2 Reduction INORGANIC CHEMISTRY Zimmerman, P. M., Zhang, Z., Musgrave, C. B. 2010; 49 (19): 8724-8728

  Abstract

  Two-hydrogen transfer (simultaneous protic and hydridic hydrogen transfer) is examined as a potentially efficient mechanism for the selective reduction of CO(2) to methanol. High-level ab initio CCSD(T) coupled-cluster theory simulations of ammonia-borane (AB), which contains both protic and hydridic hydrogen, show the effectiveness of this mechanism. AB demonstrates how simultaneous two-hydrogen transfer is kinetically efficient because (1) two-hydrogen transfer avoids high-energy single-electron-reduced intermediates, (2) the CO(2)'s HOMO is protonated while the LUMO is concurrently reduced by a hydride, and (3) complementary charge polarities around the six-membered-ring transition-state structures stabilize the transition states. This study suggests that an effective mechanism for the reduction of CO(2) to methanol proceeds through three two-hydrogen-transfer steps and that suitable catalysts should be developed that exploit two-hydrogen transfer without the use of AB.

  View details for DOI 10.1021/ic100454z

  View details for Web of Science ID 000282084600015

  View details for PubMedID 20804148

• Singlet fission in pentacene through multi-exciton quantum states NATURE CHEMISTRY Zimmerman, P. M., Zhang, Z., Musgrave, C. B. 2010; 2 (8): 648-652

  Abstract

  Multi-exciton generation-the creation of multiple charge carrier pairs from a single photon-has been reported for several materials and may dramatically increase solar cell efficiency. Singlet fission, its molecular analogue, may govern multi-exciton generation in a variety of materials, but a fundamental mechanism for singlet fission has yet to be described. Here, we use sophisticated ab initio calculations to show that singlet fission in pentacene proceeds through rapid internal conversion of the photoexcited state into a dark state of multi-exciton character that efficiently splits into two triplets. We show that singlet fission to produce a pair of triplet excitons must involve an intermediate state that (i) has a multi-exciton character, (ii) is energetically accessible from the optically allowed excited state, and (iii) efficiently dissociates into multiple electron-hole pairs. The rational design of photovoltaic materials that make use of singlet fission will require similar ab initio analysis of multi-exciton states such as the dark state studied here.

  View details for DOI 10.1038/NCHEM.694

  View details for Web of Science ID 000280199500015

  View details for PubMedID 20651727

• Excited states of methylene from quantum Monte Carlo JOURNAL OF CHEMICAL PHYSICS Zimmerman, P. M., Toulouse, J., Zhang, Z., Musgrave, C. B., Umrigar, C. J. 2009; 131 (12)

  Abstract

  The ground and lowest three adiabatic excited states of methylene are computed using the variational Monte Carlo and diffusion Monte Carlo (DMC) methods using progressively larger Jastrow-Slater multideterminant complete active space (CAS) wave functions. The highest of these states has the same symmetry, (1)A(1), as the first excited state. The DMC excitation energies obtained using any of the CAS wave functions are in excellent agreement with experiment, but single-determinant wave functions do not yield accurate DMC energies of the states of (1)A(1) symmetry, indicating that it is important to include in the wave function Slater determinants that describe static (strong) correlation. Excitation energies obtained using recently proposed pseudopotentials [Burkatzki et al., J. Chem. Phys. 126, 234105 (2007)] differ from the all-electron excitation energies by at most 0.04 eV.

  View details for DOI 10.1063/1.3220671

  View details for Web of Science ID 000270380300007

  View details for PubMedID 19791848

• Energetics of C-H Bonds Formed at Single-Walled Carbon Nanotubes NANO LETTERS Nikitin, A., Zhang, Z., Nilsson, A. 2009; 9 (4): 1301-1306

  Abstract

  We have calculated the adsorption energies for different hydrogen dimers adsorbed at the surface of zigzag single-walled carbon nanotubes (SWCNs) (n,0) (for n = 6-28) to identify the range of nanotube structural parameters that provide optimal adsorption energetics. We determined that, for H(2) gas in equilibrium with adsorbed hydrogen dimers, under normal conditions, carbon nanotubes with diameters in the range of 0.77 +/- 0.19 nm have a minimum energy overhead for hydrogen release and uptake in the hydrogen storage process. Most interestingly, we also found that the adsorption energies of hydrogen are correlated to the modulations of the nanotube density of states, because of the quantum confinement of electrons along the circumference of the SWCN. This effect is discussed from the perspective of chemical bond formation and is related to the valence to conduction band excitation energy.

  View details for DOI 10.1021/nl802727h

  View details for Web of Science ID 000265030000004

  View details for PubMedID 19281256

• Fermi Level Unpinning and Schottky Barrier Modification by Ti, Sc and V Incorporation at NiSi2/Si Interface CHINESE PHYSICS LETTERS Geng Li, L., Magyari-Kope Blanka, B., Zhang Zhi-Yong, Z. Y., Nishi Yoshio, Y. 2009; 26 (3)

  View details for Web of Science ID 000263601300066

• Oligomerization and Autocatalysis of NH2BH2 with Ammonia-Borane INORGANIC CHEMISTRY Zimmerman, P. M., Paul, A., Zhang, Z., Musgrave, C. B. 2009; 48 (3): 1069-1081

  Abstract

  The reactivity of NH(2)BH(2) in the presence of ammonia-borane (AB) is investigated using ab initio CCSD(T) simulations to answer the following three questions: How do AB and NH(2)BH(2) react? How do aminoborane species oligomerize apart from catalytic centers? Can the formation of experimentally observed products, especially cyclic N(2)B(2)H(7)-NH(2)BH(3), be explained through the kinetics of NH(2)BH(2) oligomerization in the presence of AB? AB is shown to react with NH(2)BH(2) by the addition of NH(3)-BH(3) across the N=B double bond, generating linear NH(3)BH(2)NH(2)BH(3). This species decomposes by surmounting a reasonable barrier to produce two NH(2)BH(2) and H(2). The generation of additional NH(2)BH(2) from NH(2)BH(2) and AB provides a pathway for autocatalytic NH(2)BH(2) production. The important intermediates along the oligomerization pathway include cyclic (NH(2)BH(2))(2) and linear NH(3)BH(2)NH(2)BH(3), both of which have been observed experimentally. Calculations show cyclic N(2)B(2)H(7)-NH(2)BH(3), an aminoborane analogue of ethylcyclobutane, to be the kinetically preferred stable intermediate resulting from oligomerization of free NH(2)BH(2) over its isomers, cyclic B(2)N(2)H(7)-BH(2)NH(3) and cyclotriborazane, cyclic (NH(2)BH(2))(3). Simulations show cyclotriborazane formation to be kinetically slower than cyclic B(2)N(2)H(7)-NH(2)BH(3) formation and imply that formation of the cyclic species cyclotriborazane and cyclopentaborazane may be catalyzed by binding of NH(2)BH(2) to a catalytic metal center. Routes that may lead to larger noncyclic oligomers are suggested to be kinetically competitive. The highly reactive N=B double bonds of NH(2)BH(2) are shown to be of central importance in understanding aminoborane oligomerization.

  View details for DOI 10.1021/ic801731s

  View details for PubMedID 19125668

• The Role of Free N-Heterocyclic Carbene (NHC) in the Catalytic Dehydrogenation of Ammonia-Borane in the Nickel NHC System ANGEWANDTE CHEMIE-INTERNATIONAL EDITION Zimmerman, P. M., Paul, A., Zhang, Z., Musgrave, C. B. 2009; 48 (12): 2201-2205

  Abstract

  Enders' N-heterocyclic carbene (NHC) dehydrogenates ammonia-borane with a relatively low barrier, producing NH(2)BH(2) and NHC-(H)(2). The nickel NHC catalyst present in the reaction media can activate the NHC-(H)(2) produced to regenerate the free NHC and release H(2). The release of free NHC enables further dehydrogenation of ammonia-borane.

  View details for DOI 10.1002/anie.200803211

  View details for PubMedID 19204967

• Configuration interaction studies on the electronic states of the CUO molecule MOLECULAR PHYSICS Yang, T., Tyagi, R., Zhang, Z., Pitzer, R. M. 2009; 107 (8-12): 1193-1195

  View details for DOI 10.1080/00268970902804534

  View details for Web of Science ID 000266972800046

• C-H bond formation at the graphite surface studied with core level spectroscopy SURFACE SCIENCE Nikitin, A., Naeslund, L., Zhang, Z., Nilsson, A. 2008; 602 (14): 2575-2580

  View details for DOI 10.1016/j.susc.2008.06.012

  View details for Web of Science ID 000259062200042

• Ab initio modeling of Schottky-barrier height tuning by yttrium at nickel silicide/silicon interface IEEE ELECTRON DEVICE LETTERS Geng, L., Magyari-Kope, B., Zhang, Z., Nishi, Y. 2008; 29 (7): 746-749

  View details for DOI 10.1109/LED.2008.2000647

  View details for Web of Science ID 000257626000029

• Quantum dot properties in the multiband envelope-function approximation using boundary conditions based upon first-principles quantum calculations PHYSICAL REVIEW B Flory, C. A., Musgrave, C. B., Zhang, Z. 2008; 77 (20)

  View details for DOI 10.1103/PhysRevB.77.205312

  View details for Web of Science ID 000256971800068

• Hydrogen storage in carbon nanotubes through the formation of stable C-H bonds NANO LETTERS Nikitin, A., Li, X., Zhang, Z., Ogasawara, H., Dai, H., Nilsson, A. 2008; 8 (1): 162-167

  Abstract

  To determine if carbon-based materials can be used for hydrogen storage, we have studied hydrogen chemisorption in single-walled carbon nanotubes. Using atomic hydrogen as the hydrogenation agent, we demonstrated that maximal degree of nanotube hydrogenation depends on the nanotube diameter, and for the diameter values around 2.0 nm nanotube-hydrogen complexes with close to 100% hydrogenation exist and are stable at room temperature. This means that specific carbon nanotubes can have a hydrogen storage capacity of more than 7 wt % through the formation of reversible C-H bonds.

  View details for DOI 10.1021/nl072325k

  View details for Web of Science ID 000252257700029

  View details for PubMedID 18088150

• Spin-orbit interaction with Nonlinear wave functions 47th Annual Sanibel Symposium Brozell, S. R., Shepard, R., Zhang, Z. WILEY-BLACKWELL. 2007: 3191–3202

  View details for DOI 10.1002/qua.21496

  View details for Web of Science ID 000250526000025

• Ab initio study of hydrogen interaction with pure and nitrogen-doped carbon nanotubes PHYSICAL REVIEW B Zhang, Z., Cho, K. 2007; 75 (7)

  View details for DOI 10.1103/PhysRevB.75.075420

  View details for Web of Science ID 000244533400106

• Dissociative electron attachment to the H2O molecule. I. Complex-valued potential-energy surfaces for the B-2(1), (2)A(1), and B-2(2) metastable states of the water anion PHYSICAL REVIEW A Haxton, D. J., McCurdy, C. W., Rescigno, T. N. 2007; 75 (1)

  View details for DOI 10.1103/PhysRevA.75.012710

  View details for Web of Science ID 000243894100085

• FUEL 164-Computational characterization and design of hydrogen storage in CNT and Li3N Zhang, Z., Magyari-Kope, B., Liu, H., Cho, K. AMER CHEMICAL SOC. 2006

  View details for Web of Science ID 000207781605039

• Hydrogenation of single-walled carbon nanotubes PHYSICAL REVIEW LETTERS Nikitin, A., Ogasawara, H., Mann, D., Denecke, R., Zhang, Z., Dai, H., Cho, K., Nilsson, A. 2005; 95 (22)

  Abstract

  Towards the development of a useful mechanism for hydrogen storage, we have studied the hydrogenation of single-walled carbon nanotubes with atomic hydrogen using core-level photoelectron spectroscopy and x-ray absorption spectroscopy. We find that atomic hydrogen creates C-H bonds with the carbon atoms in the nanotube walls, and such C-H bonds can be completely broken by heating to 600 degrees C. We demonstrate approximately 65 +/- 15 at % hydrogenation of carbon atoms in the single-walled carbon nanotubes, which is equivalent to 5.1 +/- 1.2 wt % hydrogen capacity. We also show that the hydrogenation is a reversible process.

  View details for DOI 10.1103/PhysRevLett.95.225507

  View details for Web of Science ID 000233458500040

  View details for PubMedID 16384236

• Nonlocal model of dissociative electron attachment and vibrational excitation of NO PHYSICAL REVIEW A Trevisan, C. S., Houfek, K., Zhang, Z., Orel, A. E., McCurdy, C. W., Rescigno, T. N. 2005; 71 (5)

  View details for DOI 10.1103/PhysRevA.71.052714

  View details for Web of Science ID 000229543600070

• Low-energy electron scattering of NO: Ab initio analysis of the (3)Sigma(-), (1)Delta, and (1)Sigma(+) shape resonances in the local complex potential model PHYSICAL REVIEW A Zhang, Z. Y., Vanroose, W., McCurdy, C. W., Orel, A. E., Rescigno, T. N. 2004; 69 (6)

  View details for DOI 10.1103/PhysRevA.69.062711

  View details for Web of Science ID 000222471400058

• Complex potential surface for the B-2(1) metastable state of the water anion PHYSICAL REVIEW A Haxton, D. J., Zhang, Z. Y., McCurdy, C. W., Rescigno, T. N. 2004; 69 (6)

  View details for DOI 10.1103/PhysRevA.69.062713

  View details for Web of Science ID 000222471400060

• Threshold vibrational excitation of CO2 by slow electrons PHYSICAL REVIEW LETTERS Vanroose, W., Zhang, Z. Y., McCurdy, C. W., Rescigno, T. N. 2004; 92 (5)

  Abstract

  Threshold structures, reminiscent of those seen in the polar hydrogen halides, have recently been observed in the cross sections for electron impact excitation of certain vibrational levels of the nonpolar CO2 molecule. These structures occur at energies outside the range where shape resonances dominate the dynamics. We propose a virtual state model that describes the multidimensional nuclear dynamics during the collision and explains quantitatively the selectivity observed in the excitation of the Fermi dyad, as well as the pattern of threshold peaks and oscillations seen in the upper levels of the higher polyads.

  View details for DOI 10.1103/PhysRevLett.92.053201

  View details for Web of Science ID 000188785200017

  View details for PubMedID 14995303

• Computational Chemistry for Nuclear Waste Characterization and Processing: Relativistic Quantum Chemistry of Actinides Harrison, R. J., Bernholdt, D. E., de Jong, W. A., Dixon, D. A., Dyall, K. G., Ermler, W. V., Fann, G. I., Hay, P. J., Ismail Buchner, N., Kendall, R. A., Li, J., Marino, M. M., Marsden, C. J., Martin, R. L., Minkoff M, Nichols, J. A., Nieplocha, J., Pitzer, R. M., Pratt, L. R., Schreckenbach, H. G., Seth, M. C., Shepard, R., Stevens, R. L., Tilson, J. L., Zhang, Z. 2002
• Electronic structure and spectra of actinyl ions JOURNAL OF PHYSICAL CHEMISTRY A Matsika, S., Zhang, Z., Brozell, S. R., Baudeau, J. P., Wang, Q., Pitzer, R. M. 2001; 105 (15): 3825-3828

  View details for DOI 10.1021/jp003085z

  View details for Web of Science ID 000168259200020

• High-level multireference methods in the quantum-chemistry program system COLUMBUS: Analytic MR-CISD and MR-AQCC gradients and MR-AQCC-LRT for excited states, GUGA spin-orbit CI and parallel CI density PHYSICAL CHEMISTRY CHEMICAL PHYSICS Lischka, H., Shepard, R., Pitzer, R. M., Shavitt, I., Dallos, M., Muller, T., Szalay, P. G., Seth, M., Kedziora, G. S., Yabushita, S., Zhang, Z. Y. 2001; 3 (5): 664-673

  View details for Web of Science ID 000167000000004

• Atomic orbital basis sets for use with effective core potentials INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY Blaudeau, J. P., Brozell, S. R., Matsika, S., Zhang, Z., PITZER, R. M. 2000; 77 (2): 516-520

  View details for Web of Science ID 000085431800002

• Computational Chemistry for Nuclear Waste Characterization and Processing: Relativistic Quantum Chemistry of Actinides proceedings of the "Fourth International Conference on Supercomputing in Nuclear Applications de Jong, W. A., Dixon, D. A., Fann, G. I., Harrison, R. J., Nichols, J., Nieplocha, J., Windus, T. L., Zhang, Z. 2000
• Application of relativistic quantum chemistry to the electronic energy levels of the uranyl ion JOURNAL OF PHYSICAL CHEMISTRY A Zhang, Z. Y., Pitzer, R. M. 1999; 103 (34): 6880-6886

  View details for Web of Science ID 000082335400025

• Spin-orbit configuration interaction using the graphical unitary group approach and relativistic core potential and spin-orbit operators JOURNAL OF PHYSICAL CHEMISTRY A Yabushita, S., Zhang, Z. Y., Pitzer, R. M. 1999; 103 (29): 5791-5800

  View details for Web of Science ID 000081766000023

• NEW REALIZATION OF LOOP DRIVEN DIRECT CI JOURNAL OF COMPUTATIONAL CHEMISTRY Wang, Y. B., Wen, Z. Y., Zhang, Z. Y., DU, Q. S. 1992; 13 (2): 187-198

  View details for Web of Science ID A1992HG19900010

• ALTERNATIVE IMPLEMENTATION OF THE UNITARY-GROUP APPROACH TO THE ATOMIC SHELL THEORY INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY Wen, Z. Y., Wang, Y. B., Zhang, Z. Y. 1990; 37 (5): 631-653

  View details for Web of Science ID A1990CZ09200002