In order to understand the electronic, dynamics and spectroscopic features of trace gases in the atmosphere, we have performed the following projects: (1) We are aiming at developing accurate molecular theory on systems containing thousands of atoms. We have continued our research in the following four directions: (i) development of new ab initio theory, particularly multireference based perturbation theory, (ii) development of exchange and correlation functionals in density functional theory, and (iii) development of molecular theory including relativistic effects, (iv) development of a program package, UTChem. (2) The initial surface reaction mechanism of atomic layer deposition of Al2O3 on Si(100) is studied using density functional theory at the level of B3LYP/6-31G(d,p). Two different aluminum precursors, Al(CH3)3 (TMA) and AlCl3 (TCA), are used with H2O. We modeled a Si(100) surface by a Si9H12 cluster and two dangling bonds on the surface were terminated by OH groups. (3) We have studied an application of femtosecond pump-probe photoelectron spectroscopy to directly observe vibrational wavepackets passing through an avoided crossing using quantum wavepacket dynamics calculations. Transfer of the vibrational wavepacket between diabatic electronic surfaces, bifurcation of the wavepacket, and wavepacket construction via nonadiabatic mixing are shown to be observable as time-dependent splittings of peaks in the photoelectron spectra.
electronic structure theory, UTChem, atomic layer deposition, high-k materials, pump-probe photoelectron spectroscopy, wavepacket splitting.