This account discusses first two computational methods which can be applied to electronic structure calculations of soft-crystals; one is a method composed of the periodic-density functional theory (DFT) for an infinite crystal and the post-Hartree-Fock method for a cluster model, named here cluster-model/periodic-model combined method (abbreviated as CM/PM-Combined method). The other is a quantum mechanics/periodic-molecular mechanics (named QM/Periodic-MM) method, in which a target molecule is calculated by the DFT or the post-Hartree-Fock method and the other moiety is calculated by the MM method under the periodic boundary condition. Then, the performance of these two methods is discussed. The CM/PM-Combined method exhibited good performance for investigating the gas adsorption into MOF and the QM/Periodic-MM succeeded in reproducing geometry of single crystal of platinum(II) complexes. The QM/periodic-MM method has been applied to theoretical studies of the excited state and the emission spectrum in soft-crystals: In a theoretical study of a gold(I) phenyl phenylisocyanide complex, the geometries of a triplet ligand-to-ligand charger transfer (³LLCT) and a triplet metal-metal to ligand charge-transfer (³MMLCT) excited states were optimized in the crystal and the dependences of absorption and emission energies on crystal phase were discussed. In a theoretical study of a platinum(II) dicyano bipyridine complex, the geometries of several delocalized ³MMLCT excited states, emission spectra, and their temperature dependences were investigated in the crystal. In both gold(I) and platinum(II) complexes, the characteristic features of the excited state and the emission spectra were elucidated by the theoretical calculations. Although the CM/PM-Combined method has not been applied to photochemistry issue, brief discussion is presented for its possibility for the application.

本文讨论了可应用于软晶体电子结构计算的前两种计算方法；一种是由无限晶体的周期密度泛函理论（DFT）和簇模型的后Hartree-Fock方法组成的方法，这里命名为簇模型/周期模型组合方法（简称CM/PM-组合法）。另一种是量子力学/周期分子力学（称为QM/Periodic-MM）方法，其中目标分子通过DFT或post-Hartree-Fock方法计算，另一部分通过MM方法计算周期性边界条件。然后，讨论这两种方法的性能。CM/PM-Combined 方法在研究 MOF 中的气体吸附方面表现出良好的性能，QM/Periodic-MM 成功地再现了铂 (II) 配合物单晶的几何形状。QM/periodic-MM 方法已应用于软晶体中激发态和发射光谱的理论研究：充电器转移（³ LLCT)和三线态金属-金属到配体电荷转移( ³ MMLCT)激发态在晶体中进行了优化，并讨论了吸收和发射能量对晶相的依赖性。在对铂 (II) 二氰基联吡啶配合物的理论研究中，研究了晶体中几种离域³ MMLCT 激发态、发射光谱及其温度依赖性的几何形状。在金（I）和铂（II）配合物中，通过理论计算阐明了激发态和发射光谱的特征。虽然 CM/PM-Combined 方法尚未应用于光化学问题，但对其应用可能性进行了简要讨论。