为了说明两态反应会影响甚至决定整个反应的反应速率或选择性，运用密度泛函（DFT ）B3lyp／6‐311＋ G （3df ，2p）方法，对TiO催化CO2加氢生成甲酸反应的单、三重态各个驻点结构进行优化。发现在两个自旋态势能面之间有四处能量交叉点（CPs），由此找出最低能量交叉点（MECP），根据交叉点的构型计算自旋‐轨道耦合（SOC）常数，用Landau‐Zener非绝热跃迁公式计算出M ECP处的跃迁几率，发现四处最低能量交叉点都具有较强的自旋‐轨道耦合作用和较高的跃迁几率，且四个最低能量交叉点处电子的自旋翻转均发生在Ti原子不同的d轨道之间，确定了最低能量反应路径。用能量跨度模型计算了在298 K下TiO的转化频率（TOF）及整个过程的控制度（XTOF ），同时确定了整个反应过程中的决速态。%To illustrate the two state reaction will influence and even determine the reaction rate of the whole or selectivity ,the density functional method(DFT) B3lyp/6‐311+ G(3df ,2p) is used to optimize CO2 hydrogenation to generate formate catalyzed by TiO of singlet and triplet stagnation point structure in the gas phase .Under the whole catalytic cycle ,there are four crossing points between singlet and triplet potential energy surfaces . T he possibilities of spin flip at M ECPs are discussed through spin‐orbit coupling calculations . T he electron transition probability are calculated by Landau‐Zener formula , 4 M ECPs has strong spin‐orbit coupling effect and higher transition probability , and all spin inversion is occurred in different d orbits of titanium . Finally , the lowest energy reaction path is ensured . The turnover frequency(TOF) and XTOF at 298 K have been obtained by citing the energetic span model proposed by Kozuch . T he fast mode in the process of reaction is determined .
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