Monte Carlo configuration interaction predictions for the electronic spectra of Ne, CH2, C2, N2, and H2O compared to full configuration interaction calculations.
Monte Carlo configuration interaction predictions for the electronic spectra of Ne, CH2, C2, N2, and H2O compared to full configuration interaction calculations.
复制标题
Ne、CH2、C2、N2 和 H2O 电子光谱的蒙特卡罗构型相互作用预测与完整构型相互作用计算的比较。
作者：
W. Győrffy;R. Bartlett;J. Greer
用蒙特卡罗组态相互作用(CI)方法计算了Ne、CH(2)、C(2)、N(2)和H(2)O的单态和三态电子激发能。我们发现，与相应的FCI展开式中的O(10(8))组态相比，使用只有几千个组态函数的展开式可以预测激发能在全CI(FCI)结果的几十meV内。对于小分子体系，该方法提供了一致准确和平衡的电子激发描述，其精度可与全三重运动方程耦合团簇方法相媲美。
Singlet and triplet electronic excitation energies have been calculated for Ne, CH(2), C(2), N(2), and H(2)O using the Monte Carlo configuration interaction (CI) method. We find that excitation energies can be predicted to within a few tens of meV of full CI (FCI) results using expansions consisting of only a few thousand configuration state functions as compared to the O(10(8)) configurations occurring in the corresponding FCI expansions. The method provides a consistently accurate and balanced description of electronic excitations with accuracy for small molecular systems comparable to the equation-of-motion coupled cluster method with full triples.