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Full-Text Articles in Physics
Full Correlation In A Multiconfigurational Study Of Bimetallic Clusters : Restricted Active Space Pair-Density Functional Theory Study Of [2fe-2s] Systems, Samuel J. Stoneburner, Davide Presti, Donald G. Truhlar, Laura Gagliardi
Full Correlation In A Multiconfigurational Study Of Bimetallic Clusters : Restricted Active Space Pair-Density Functional Theory Study Of [2fe-2s] Systems, Samuel J. Stoneburner, Davide Presti, Donald G. Truhlar, Laura Gagliardi
Educator Scholarship
Iron-sulfur clusters play a variety of important roles in protein chemistry, and understanding the energetics of their spin ladders is an important part of understanding these roles. Computational modeling can offer considerable insight into such problems; however, calculations performed thus far on systems with multiple transition metals have typically either been restricted to a single-configuration representation of the density, as in Kohn-Sham theory, or been limited to correlating excitations only within an active space, as in active-space self-consistent field methods. For greater reliability, a calculation should include full correlation, i.e., not only correlation internal to the active space but also …
Beyond Density Functional Theory: The Multiconfigurational Approach To Model Heterogeneous Catalysis, Samuel J. Stoneburner, Carlo Alberto Gaggioli, Christopher J. Cramer, Laura Gagliardi
Beyond Density Functional Theory: The Multiconfigurational Approach To Model Heterogeneous Catalysis, Samuel J. Stoneburner, Carlo Alberto Gaggioli, Christopher J. Cramer, Laura Gagliardi
Educator Scholarship
Catalytic processes are crucially important for many practical chemical applications. Heterogeneous catalysts are especially appealing because of their high stability and the relative ease with which they may be recovered and reused. Computational modeling can play an important role in the design of more catalytically active materials through the identification of reaction mechanisms and the opportunity to assess hypothetical catalysts in silico prior to experimental verification. Kohn-Sham density functional theory (KS-DFT) is the most used method in computational catalysis because it is affordable and it gives results of reasonable accuracy in many instances. Furthermore, it can be employed in a …
Mass-Analyzed Threshold Ionization Of Lanthanide Imide Lnnh (Ln = La And Ce) Radicals From N–H Bond Activation Of Ammonia, Yuchen Zhang, Silver Nyambo, Dong-Sheng Yang
Mass-Analyzed Threshold Ionization Of Lanthanide Imide Lnnh (Ln = La And Ce) Radicals From N–H Bond Activation Of Ammonia, Yuchen Zhang, Silver Nyambo, Dong-Sheng Yang
Chemistry Faculty Publications
Ln (Ln = La and Ce) atom reactions with ammonia are carried out in a pulsed laser vaporization supersonic molecular beam source. Lanthanide-containing species are observed with time-of-flight mass spectrometry, and LnNH molecules are characterized by mass-analyzed threshold ionization (MATI) spectroscopy and quantum chemical calculations. The theoretical calculations include density functional theory for both Ln species and a scalar relativity correction, electron correlation, and spin-orbit coupling for the Ce species. The MATI spectrum of LaNH exhibits a single vibronic band system with a strong origin band and two weak vibronic progressions, whereas the spectrum of CeNH displays two band systems …
Mc-Pdft Can Calculate Singlet-Triplet Splittings Of Organic Diradicals., Samuel J. Stoneburner, Donald G. Truhlar, Laura Gagliardi
Mc-Pdft Can Calculate Singlet-Triplet Splittings Of Organic Diradicals., Samuel J. Stoneburner, Donald G. Truhlar, Laura Gagliardi
Educator Scholarship
The singlet-triplet splittings of a set of diradical organic molecules are calculated using multiconfiguration pair-density functional theory (MC-PDFT) and the results are compared with those obtained by Kohn-Sham density functional theory (KS-DFT) and complete active space second-order perturbation theory (CASPT2) calculations. We found that MC-PDFT, even with small and systematically defined active spaces, is competitive in accuracy with CASPT2, and it yields results with greater accuracy and precision than Kohn-Sham DFT with the same parent functional. MC-PDFT also avoids the challenges associated with spin contamination in KS-DFT. It is also shown that MC-PDFT is much less computationally expensive than CASPT2 …