Direct calculation of coupled diabatic potential-energy surfaces for ammonia and mapping of a four-dimensional conical intersection seam.
Direct calculation of coupled diabatic potential-energy surfaces for ammonia and mapping of a four-dimensional conical intersection seam.
复制标题
氨的耦合非绝热势能面的直接计算和四维锥形交叉缝的映射。
DOI：
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发表时间：
2006
影响因子：
4.4
通讯作者：
D. Truhlar
中科院分区：
文献类型：
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作者：
S. Nangia;D. Truhlar
我们使用多组态准生微扰理论和四重直接非绝热化方案计算了NH3在3600个核几何构型下的从头算势能面。计算得到了基态和第一电子激发单重态的绝热和非绝热势能面以及非绝热耦合面。非绝热表面和耦合解析拟合的功能形式，以获得一个置换不变的2 × 2非绝热势能矩阵。然后通过对角化非绝热势能矩阵得到绝热势能面的解析表示。曲面的解析表示给出了四维圆锥相交缝的解析表示，并对该解析表示进行了详细讨论。
We used multiconfiguration quasidegenerate perturbation theory and the fourfold-way direct diabatization scheme to calculate ab initio potential-energy surfaces at 3600 nuclear geometries of NH3. The calculations yield the adiabatic and diabatic potential-energy surfaces for the ground and first electronically excited singlet states and also the diabatic coupling surfaces. The diabatic surfaces and coupling were fitted analytically to functional forms to obtain a permutationally invariant 2 x 2 diabatic potential-energy matrix. An analytic representation of the adiabatic potential-energy surfaces is then obtained by diagonalizing the diabatic potential-energy matrix. The analytic representation of the surfaces gives an analytic representation of the four-dimensional conical intersection seam which is discussed in detail.