A5035326725- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Advanced Chemical Physics Studies
- Spectroscopy and Quantum Chemical Studies
- Organometallic Complex Synthesis and Catalysis
- Crystallography and molecular interactions
- Advanced NMR Techniques and Applications
- Quantum and electron transport phenomena
- Radioactive element chemistry and processing
- Synthesis and characterization of novel inorganic/organometallic compounds
- Coordination Chemistry and Organometallics
- Magnetism in coordination complexes
- Inorganic Chemistry and Materials
- Molecular Spectroscopy and Structure
- Quantum Computing Algorithms and Architecture
- Molecular spectroscopy and chirality
- Spine and Intervertebral Disc Pathology
- Quantum Information and Cryptography
- Spinal Fractures and Fixation Techniques
- Lanthanide and Transition Metal Complexes
- Machine Learning in Materials Science
- Physics of Superconductivity and Magnetism
- Chemical Synthesis and Characterization
- Mesoporous Materials and Catalysis
- Quantum, superfluid, helium dynamics
Rice University
2021-2024
Atlanta University Center
2022
Emory University
2022
University of California, Irvine
2017-2020
Tsinghua University
2013-2017
The First Hospital of Kunming
2009-2011
TURBOMOLE is a collaborative, multi-national software development project aiming to provide highly efficient and stable computational tools for quantum chemical simulations of molecules, clusters, periodic systems, solutions. The suite optimized widely available, inexpensive, resource-efficient hardware such as multi-core workstations small computer clusters. specializes in electronic structure methods with outstanding accuracy-cost ratio, density functional theory including local hybrids...
Random-phase approximation (RPA) methods are rapidly emerging as cost-effective validation tools for semilocal density functional computations. We present the theoretical background of RPA in an intuitive rather than formal fashion, focusing on physical picture screening and simple diagrammatic analysis. A new decomposition correlation energy into plasmonic modes leads to appealing visualization electron terms charge fluctuations. Recent developments areas beyond-RPA methods, potentials,...
STUDY DESIGN.: Prospective trial. OBJECTIVE.: To develop and validate a novel, patient-specific navigational template for cervical pedicle placement. SUMMARY OF BACKGROUND DATA.: Owing to the narrow bony anatomy proximity vertebral artery spinal cord, instrumentation procedures demand need precise technique screw PATIENT.: Specific drill with preplanned trajectory has been thought as promising solution METHODS.: Patients pathology (n = 25) requiring were recruited. Volumetric CT scan was...
Over 70 years of chemical investigations have shown that plutonium exhibits some the most complicated chemistry in periodic table. Six Pu oxidation states been unambiguously confirmed (0 and +3 to +7), four different can exist simultaneously solution. We report a new formal state for plutonium, namely Pu2+ [K(2.2.2-cryptand)][PuIICp″3], Cp″ = C5H3(SiMe3)2. The synthetic precursor PuIIICp″3 is also reported, comprising first structural characterization Pu–C bond. Absorption spectroscopy DFT...
Objective: To develop and validate the efficacy accuracy of a novel drill template for cervical pedicle instrumentation.Materials Methods: A CT scan vertebrae was performed, 3D model reconstructed using MIMICS 10.01 software. The vertebral then exported in STL format, opened workstation running UGS Imageware 12.0 software to determine optimal screw size orientation. virtual navigational established according laminar anatomic trait, physical templates were manufactured rapid prototyping. used...
Abstract The first crystallographically characterizable complex of Sc 2+ , [Sc(NR 2 ) 3 ] − (R=SiMe ), has been obtained by LnA /M reactions (Ln=rare earth metal; A=anionic ligand; M=alkali metal) involving reduction Sc(NR with K in the presence 2.2.2‐cryptand (crypt) and 18‐crown‐6 (18‐c‐6) Cs crypt. Dark maroon [K(crypt)] + [K(18‐c‐6)] [Cs(crypt)] salts anion are formed, respectively. formation this oxidation state is also indicated eight‐line EPR spectra arising from I =7/2 45 nucleus....
A new series of Ln2+ complexes has been synthesized that overturns two previous generalizations in rare-earth metal reduction chemistry: amide ligands do not form isolable the highly reducing non-traditional ions, and yttrium is a good model for late lanthanides these reductive reactions. Reduction Ln(NR2 )3 (R=SiMe3 ) THF under Ar with M=K or Rb presence 2.2.2-cryptand (crypt) forms crystallographically characterizable [M(crypt)][Ln(NR2 ] only traditional Tm2+ ion configurational crossover...
Prompted by recent reports of large errors in noncovalent interaction (NI) energies obtained from many-body perturbation theory (MBPT), we compare the performance second-order Mo̷ller-Plesset MBPT (MP2), spin-scaled MP2, dispersion-corrected semilocal density functional approximations (DFAs), and post-Kohn-Sham random phase approximation (RPA) for predicting binding supramolecular complexes contained S66, L7, S30L benchmarks. All are extrapolated to basis set limit, corrected superposition...
Abstract Background The great accuracy of computer‐assisted operative systems for pedicle screw insertion makes them highly desirable spinal surgeries. However, placement is expensive, and the learning curve these techniques significant. We have developed a novel method stereotaxy by reverse engineering (RE) rapid prototyping (RP) validated method's cadaveric clinical study. Methods A volumetric CT scan was performed on each desired lumbar vertebra three‐dimensional (3D) reconstruction model...
The Th3+ complex, (C5Me5)3Th, has been isolated despite the fact that tris(pentamethylcyclopentadienyl) complexes are highly reactive due to steric crowding and few crystallographically characterizable known their reducing nature. Reaction of (C5Me5)2ThMe2 with [Et3NH][BPh4] produces cationic thorium complex [(C5Me5)2ThMe][BPh4] can be treated KC5Me5 generate (C5Me5)3ThMe, 1. methyl group on (C5Me5)3ThMe removed form [(C5Me5)3Th][BPh4], 2, first metal which reduced KC8 yield 3. Complexes 1–3...
The first (N═N)2– complex of a rare-earth metal with an end-on dinitrogen bridge, {K(crypt)}2{[(R2N)3Sc]2[μ-η1:η1-N2]} (crypt = 2.2.2-cryptand, R SiMe3), has been isolated from the reduction Sc(NR2)3 under at −35 °C and characterized by X-ray crystallography. structure differs characteristic side-on structures previously observed for over 40 crystallographically complexes formula [A2Ln(THF)x]2[μ-η2:η2-N2] (Ln Sc, Y, lanthanides; x 0, 1; A anionic ligand such as amide, cyclopentadienide,...
The synthesis of 4fn Ln3+ complexes the tris(aryloxide) mesitylene ligand, ((Ad,MeArO)3mes)3–, with Ln = La, Ce, Pr, Sm, and Yb, their reduction potassium have revealed that this ligand system can be redox active some metals. Protonolysis [Ln(N(SiMe3)2)3] (Ln Yb) tris(phenol) (Ad,MeArOH)3mes yielded [((Ad,MeArO)3mes)Ln] Yb), 1-Ln. Single electron each complex, 1-Ln, using reduced products, [K(2.2.2-cryptand)][((Ad,MeArO)3mes)Ln] 2-Ln. Sm Yb properties consistent presence Ln2+ ions...
Strong variation of actinide f-orbital energy-levels with nuclear AND ionic charges lowers the highest possible oxidation-states from Pu onwards.
We consider the implications of Lieb-Simon limit for correlation in density functional theory. In this limit, exemplified by scaling neutral atoms to large atomic number, local approximation (LDA) becomes relatively exact, and leading correction has recently been determined atoms. use LDA properties real-space cutoff exchange-correlation hole design, based upon Perdew-Burke-Ernzerhof (PBE) correlation, an asymptotically corrected generalized gradient (acGGA) which more accurate per electron...
Numerical difficulties associated with computing matrix elements of operators between Hartree-Fock-Bogoliubov (HFB) wavefunctions have plagued the development HFB-based many-body theories for decades. The problem arises from divisions by zero in standard formulation nonorthogonal Wick's theorem limit vanishing HFB overlap. In this Communication, we present a robust that stays well-behaved regardless whether states are orthogonal or not. This new ensures cancellation zeros overlap and poles...
It is usually asserted that physical Hamiltonians for fermions must contain an even number of fermion operators. This indeed true in electronic structure theory. However, when the Jordan-Wigner (JW) transformation used to map spin spinless fermions, terms odd operators may appear. The resulting fermionic Hamiltonian thus does not have parity symmetry and requires wave functions do this either. In work, we discuss extension standard Hartree-Fock-Bogoliubov (HFB) theory...
Electronic structure methods typically benefit from symmetry breaking and restoration, specially in the strong correlation regime. The same goes for Ans\"atze on a quantum computer. We develop unitary coupled cluster method antisymmetrized geminal power (AGP) -- state formally equivalent to number-projected Bardeen--Cooper--Schrieffer wavefunction. demonstrate our single-band Fermi--Hubbard Hamiltonian one two dimensions. also explore post-selection as preparation step obtain correlated AGP...
The antisymmetrized geminal power (AGP), a wave function equivalent to number-projected Hartree-Fock-Bogoliubov (HFB), and Bardeen-Cooper-Schrieffer (BCS) when working in the paired (natural orbitals) basis, has proven be an excellent reference for strong pairing interactions. Several correlation methods have also been applied on top of AGP. In this work, we show how AGP can spin systems by simply basing its formulation $su(2)$ algebra. We here implement AGP-based techniques benchmark them...
It has been suspected since the early days of random-phase approximation (RPA) that corrections to RPA correlation energies result mostly from short-range effects and are thus amenable perturbation theory. Here we test this hypothesis by analyzing formal numerical results for most common beyond-RPA perturbative corrections, including bare second-order exchange (SOX), screened (SOSEX), approximate kernel (AXK) methods. Our analysis is facilitated efficient robust algorithms based on...
We show how to construct a linearly independent set of antisymmetrized geminal power (AGP) states, which allows us rewrite our recently introduced replacement models as linear combinations non-orthogonal AGPs. This greatly simplifies the evaluation matrix elements and permits introduce an AGP-based selective configuration interaction method, can reach arbitrary excitation levels relative reference AGP, balancing accuracy cost we see fit.
Abstract The first crystallographically characterizable complex of Sc 2+ , [Sc(NR 2 ) 3 ] − (R=SiMe ), has been obtained by LnA /M reactions (Ln=rare earth metal; A=anionic ligand; M=alkali metal) involving reduction Sc(NR with K in the presence 2.2.2‐cryptand (crypt) and 18‐crown‐6 (18‐c‐6) Cs crypt. Dark maroon [K(crypt)] + [K(18‐c‐6)] [Cs(crypt)] salts anion are formed, respectively. formation this oxidation state is also indicated eight‐line EPR spectra arising from I =7/2 45 nucleus....
The Jordan–Wigner transformation establishes a duality between su(2) and fermionic algebras. We present qualitative arguments numerical evidence that when mapping spins to fermions, the makes strong correlation weaker, as demonstrated by Hartree–Fock approximation transformed Hamiltonian. This result can be rationalized in terms of rank reduction spin shift fermions. Conversely, fermions qubits stronger, complicating its solution one uses qubit-based correlators. presence string operators...
Prompted by recent reports of large errors in noncovalent interaction (NI) energies obtained from many-body perturbation theory (MBPT), we compare the performance second-order Møller–Plesset MBPT (MP2), spin-scaled MP2, dispersion-corrected semilocal density functional approximations (DFA), and post-Kohn–Sham random phase approximation (RPA) for predicting binding supramolecular complexes contained S66, L7, S30L benchmarks. All are extrapolated to basis set limit, corrected superposition...
[Y(N(SiMe3)2)3] reacts with (Ad,MeArOH)3mes to form the Y3+ complex [((Ad,MeArO)3mes)Y], 1-Y. This potassium metal in presence of 2.2.2-cryptand give a cocrystallized mixture [K(2.2.2-cryptand)][((Ad,MeArO)3mes)Y], 2-Y, and [K(2.2.2-cryptand)][((Ad,MeArO)3mes)YH], 3-Y. The electron paramagnetic resonance spectrum this crystalline exhibits an isotropic signal at 77 K ( giso = 2.000, Wiso 1.8 mT), suggesting that 2-Y is best described as tris(aryloxide)mesitylene radical ((Ad,MeArO)3mes)4-....