Xiaosong Li

SESSION: PHYSICAL CHEMISTRY POSTER:  

Vibrational quantum coherence prepared by impulsive photoexcitation provides fundamental information on the vibrationally structured potential energy surface (PES) along excited-state trajectories…

Liquid water is involved in almost all biological and chemical processes. Understanding radiation-induced chemical processes in condensed phase has importance for applications ranging from cancer therapies and space travel to environmental remediation of legacy nuclear waste…

Many transition metal complexes have metal-to-ligand charge transfer (MLCT) excited states with superior photochemical properties such as high absorption in the solar spectrum and long excited-state lifetimes, making them suitable for energy conversion…

X-ray absorption spectroscopy is a powerful probe of local electronic and nuclear structure, providing insights into chemical processes…

Transition metal complexes have been used as building blocks in artificial photosynthetic systems, functioning as light sensitizers and catalytic centers for converting sunlight to electricity and fuels…

The study of late-row elements and their chemistry is complicated by the presence of significant relativistic effects. The magnitude of these effects may be beyond the perturbative regime and require a variational treatment in order to obtain an accurate description of chemical properties…

As the relativistic effects become larger, and therefore the corrections become stronger for late-row elements, the fully perturbative treatment of spin-orbit coupling and dynamic correlation may become inadequate for accurate descriptions of chemical properties…

Division/Committee: [COMP] Division of Computers in Chemistry

Division/Committee: [COMP] Division of Computers in Chemistry

Division/Committee: [COMP] Division of Computers in Chemistry

Division/Committee: [COMP] Division of Computers in Chemistry

The need for relativistic Hamiltonians in the calculation of the electronic structure of heavy elements is already well established. For calculating X-ray spectroscopies, such as absorption (XAS) and emission (XES), these effects are even more pronounced due to the participation of core electrons…

X-ray absorption spectroscopy is a powerful probe of local electronic and nuclear structure, providing insights into bonding and chemical processes…

As the relativistic effects become larger, and therefore the corrections become stronger for late-row elements, the fully perturbative treatment of spin-orbit coupling and dynamic correlation may become inadequate for accurate descriptions of chemical properties…

While variational 4-component methods can yield meV to sub-meV accuracy, the additional computational cost prevents their more widespread use in quantum chemistry. In addition to the cost, there are unique technical challenges that arise in solving the Dirac equation variationally…

Division/Committee: [COMP] Division of Computers in Chemistry

Perturbative treatments of spin-orbit coupling (SOC) are very successful for spectroscopies of transition metals-containing complexes. However, it is unclear how far down the periodic table one can go and still achieve chemical accuracy (0.037 eV) or spectroscopic accuracy (0…

Lanthanide/actinide contraction is related to the smaller effective atomic radii of lanthanides/actinides as the _f_ shell becomes filled. This effect manifests itself at the molecular level as a decreased bond length (e.g., rLa-X > rLu-X)…

While variational 4-component methods can yield meV to sub-meV accuracy, the additional computational cost prevents their more widespread use in quantum chemistry. In addition to the cost, there are unique technical challenges that arise in solving the Dirac equation variationally…

: [COMP] Division of Computers in Chemistry

: [COMP] Division of Computers in Chemistry

While variational 4-component methods can yield meV to sub-meV accuracy, the additional computational cost prevents their more widespread use in quantum chemistry. In addition to the cost, there are unique technical challenges that arise in solving the Dirac equation variationally…

: [COMP] Division of Computers in Chemistry

: [COMP] Division of Computers in Chemistry

While variational 4-component methods can yield meV to sub-meV accuracy, the additional computational cost prevents their more widespread use in quantum chemistry. In addition to the cost, there are unique technical challenges that arise in solving the Dirac equation variationally…

DIVISION/COMMITTEE: [COMP] Division of Computers in Chemistry

Perturbative treatments of spin-orbit coupling (SOC) are very successful for spectroscopies of transition metals-containing complexes. However, it is unclear how far down the periodic table one can go and still achieve chemical accuracy (0.037 eV) or spectroscopic accuracy (0…

Lanthanide/actinide contraction is related to the smaller effective atomic radii of lanthanides/actinides as the _f_ shell becomes filled. This effect manifests itself at the molecular level as a decreased bond length (e.g., rLa-X > rLu-X)…

X-ray absorption near edge structure (XANES) spectroscopy has become a powerful tool to provide detailed information of the local electronic structure and oxidation state of a system…

Spin-orbit coupling (SOC) is important for spectroscopy and electronic structure of heavy-element-containing complexes. However, efficiently incorporating SOC in an electronic structure calculation is still a challenge…

Thiosquarines stand out as promising contenders in the quest for upconverting sensitizer dyes capable of enhancing solar cell efficiency. Thiosquarines can undergo intersystem crossing and subsequently triplet-triplet annihilation to yield high-energy fluorescent singlets…

Nuclear quantum effects and solvent environments play fundamental roles in the mechanisms of many chemical processes. We combine the nuclear-electronic orbital (NEO) method which treats select nuclei and electrons on the same quantum mechanical footing with a polarizable environment…

Resolution-of-identity (RI) methods, such as the Cholesky decomposition (CD) and density fitting (DF), are commonly used to reduce the memory requirement for storing two-particle repulsion integrals in quantum chemistry calculations that use atomic orbital bases…

Spectroscopy of actinides is a challenge to accurately model due to the strong dependence of spin-orbit coupling (SOC) and electron correlation…

The ChronusQuantum (CQ) software is an open-source tool under the GNU General Public License v2, designed for solving complex problems in ab initio electronic structure theory…

The talk will touch the following two topics:

Molecules that exhibit strong relativistic effects are challenging to describe using conventional electronic structure techniques…

Nanoparticles are at the forefront of nanotechnology research due to their unique electronic and optical properties. Among them, gold nanoparticles (AuNPs) stand out for their low toxicity, biocompatibility, and inertness, which makes them suitable for use as biosensors and in cancer treatment…

The scientific mission of the Ion Dynamics in Radioactive Environments and Materials (IDREAM) Energy Frontier Research Center is _to master the cascade of radiation chemistry that drives far-from-equilibrium speciation and reactivity in chemically complex environments, linking attosecond timescales…

Many excited state transition metal complexes exhibit significant structural changes resulting from electron density shifts upon photoexcitation, which can drive intersystem crossing (ISC) and photoinduced charge transfer (PET) and alter the metal center’s oxidation state…