Theory of ultrafast process in chemical dynamics

点击翻译按钮获取中文摘要

1) Femtosecond time-resolved photoelectron spectroscopy study on real time passage of nuclear wave packets across the conical intersection of NO2Time-resolved photoelectron spectroscopy and its photoelectron imaging are theoretically produced in terms of three dimensional quantum wavepacket dynamics on two coupled potential energy surfaces along with ab initio photoelectron amplitudes. This highlights the current progress of theoretical studies in pump-probe studies on chemical reaction dynamics. We have also proposed an optical conversion of the conical intersection to an avoided crossing.[Y. Arasaki, K. Takatsuka, K. Wang, and V. McKoy, "Tracking vibrational wavepacket dynamics through a conical interaction in NO2 with angle-resolved pump-probe photoelectron spectroscopy", J. Chem. Phys. accepted for publication. Yasuki Arasaki and Kazuo Takatsuka, Phys. Chem. Chem. Phys. (Communication), 12, 1239-1242 (2010).]2) A new statistical theory of evaporation from atomic clustersWe have dev … More eloped a new statistical theory of atomic and diatomic molecule evaporation from an atomic cluster, in which the time scale of evaporation competes with that of structural isomerization. Therefore the standard statistical theory such as the transition state theory, cannot be applied.[Mikiya Fujii and Kazuo Takatsuka, J. Chem. Phys., 127, 204309 (7 pages) (2007); Mikiya Fujii and Kazuo Takatsuka, J. Phys. Chem. A 111, 1389-1402 (2007); Mikiya Fujii and Kazuo Takatsuka, J. Chem. Phys. 128, 114318 (15 pages) (2008).]3) Mechanism of quantization of classical chaosMechanism of quantization of classical chaos has been clarified through our own semiclassical approach. It turns out that the amplitude factor that destroys the spectrum in semiclassical theory does not play a major role in quantization and can be simply discarded in numerical calculations.[Kazuo Takatsuka, Satoshi Takahashi, Yang Wei Koh, and Takefumi Yamashita, J. Chem. Phys. (communication) 126, 021104 (4 pages) (2007); Takefumi Yamashita and Kazuo Takatsuka, Prog. Theoret. Phys. Supplement. 166, 56-69 (2007); Satoshi Takahashi and Kazuo Takatsuka, J. Chem. Phys. 127, 084112 (13 pages) (2007).]4) On the validity of the Born-Oppenheimer approximationWe have found why the Born-Oppenheimer approximation is so good an approximation. The error contained is proportional to the power of 1.5 of m/M, where m and M are the mass of electron and nuclei, respectively.[Satoshi Takahashi and Kazuo Takatsuka, J. Chem. Phys. 124, 144101 (14 pages) (2006).]5) Nonadiabatic electron wavepacket dynamics in intense laser fieldAn ab inito theory for electron wavepacket dynamics coupled with nuclear motion in intense laser field has been formulated, and numerically applied to several molecular systems. This theory sets a theoretical foundation with which to control chemical reactions through the control of electronic states.[Kazuo Takatsuka and Takehiro Yonehara, Adv. Chem. Phys. 144, 93-156, (2009). Takehiro Yonehara and Kazuo Takatsuka, Chem. Phys. 366, 114-128 (2009).]6) Establishing non-Born-Oppenheimer quantum chemistry for electronic and nuclear wavepacketsUnifying the above electron wavepacket propagated along the branching paths and the semiclassical quantization of the branching nuclear path in terms ADF, we have formulated our general and practical scheme of non-Born-Oppenheimer electronic and nuclear wavepacket dynamics. The theory has been actually implemented in GAMESS code and numerically tested. We are now in a new stage of quantum chemistry for excited states.[Kazuo Takatsuka, Intern. J. Quant. Chem. 109, 2131-2142 (2009). Takehiro Yonehara, Satoshi Takahashi and Kazuo Takatsuka, J. Chem. Phys. 130, 214113 (2009).]7) Non-Born-Oppenheimer quantum chemistry in intense laser fieldsThe theory of non-Born-Oppenheimer quantum chemistry has been generalized so as to be able to treat chemical reactions in laser fields.[“Non-Born-Oppenheimer quantum chemistry on the fly with continuous path branching due to nonadiabatic and intense optical interactions." Tahehiro Yonehara and Kazuo Takatsuka, J. Chem. Phys. in press (2010). ] Less