外场下二甲基硅酮双自由基的从头计算研究

摘要

本文首先采用密度泛函(DFT)方法在6-311+g(2d,p)基组水平上计算研究了二甲基硅酮双自由基的红外振动光谱和核磁共振化学位移,而后在同样的基组水平上采用含时密度泛函(TDDFT)方法研究了外电场对二甲基硅酮双自由基的激发态、偶极矩和分子能量的影响,结果表明,不同方向的外加电场对他们的影响情况各不相同,沿X、Y方向的电场对激发态的激发能、振子强度影响在外加电场为0.005～0.010 a.u.是转折点,沿Z方向的电场在电场强度为0.015 a.u.是转折点.沿Y方向的外电场对分子的偶极矩、分子能量影响最大,沿X方向的外电场次之,沿Z方向的外电场对偶极矩和分子能量影响最小.%Infrared spectrum and NMR chemical shifts of Si(CH3)2O double free radical were calculated employing density functional theory(DFT) with the basis sets 6-31 1+G(2d,p). Excited states, dipole moment and energy of Si(CH3)2O double free radical were also calculated using time dependent density function theory (TD-D FT) with the same basis sets. It is found that the external electric field along the X,Y and Z axis affect differently on the excited states and other properties of Si(CH3)2O double free radical.