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Physical Chemistry Seminar- Prof. Yang Yang, UW-Madison
February 16, 2021 @ 11:00 am - 12:00 pm
Prof. Yang Yang
University of Wisconsin – Madison
Physical Chemistry, Seminar
PHYSICAL CHEMISTRY SEMINAR – “INCORPORATE NUCLEAR QUANTUM EFFECTS ON ENERGY SURFACES WITH CONSTRAINED NUCLEAR-ELECTRONIC ORBITAL DENSITY FUNCTIONAL THEORY”
The nuclear quantum effects play an important role in many chemical and biological processes. The nuclear-electronic orbital density functional theory (NEO-DFT) can describe the nuclear quantum effects through a consistent quantum mechanical treatment of more than one type of particle. However, the conventional NEO-DFT requires a classical treatment of at least two nuclei and therefore invokes an unphysical Born-Oppenheimer separation between classical and quantum nuclei. We developed constrained NEO-DFT (cNEO-DFT) by applying a constraint on the expectation position for each quantum nucleus. In this way, a full-quantum treatment for all nuclei can be achieved, which avoids any Born-Oppenheimer separation. Furthermore, the total energy surface for full-quantum cNEO-DFT naturally includes the nuclear quantum effects, especially zero-point effects, for all nuclei, which have a notable effect on both equilibrium geometries and reaction barriers. Therefore, cNEO-DFT is capable of describing both geometric isotope effects and kinetic isotope effects. In addition, the vibrational frequencies obtained from diagonalizing the cNEO-DFT Hessian is more accurate than conventional DFT, indicating the importance of nuclear quantum effects even for some simple molecular vibrations.
FOR MORE INFORMATION, PLEASE CONTACT: LIV WEST AT OBWEST@WISC.EDU