Free complement sij-assisted rij theory: Variational calculation of the quintet state of a carbon atom
Free complement sij-assisted rij theory: Variational calculation of the quintet state of a carbon atom
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自由补体 sij 辅助 rij 理论：碳原子五重态的变分计算
DOI：
10.1103/physreva.102.052835
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发表时间：
2020
影响因子：
2.9
通讯作者：
Hiroyuki Nakashima and Hiroshi Nakatsuji
中科院分区：
文献类型：
--
作者：
Hiroshi Nakatsuji;Hiroyuki Nakashima;and Yusaku I. Kurokawa;Hiroyuki Nakashima and Hiroshi Nakatsuji
自由互补辅助（）理论是作为求解原子和分子薛定谔方程的变分方法而发展起来的。该理论只允许在每个补函数（cf）中有一个相关项，而其他项则用项代替，这样变分计算就可以在一到四个电子积分范围内进行。我们开发了扩展的Löwdin公式的反对称化包括非正交函数和实施一至四个电子的斯莱特原子积分代码本计算所需的。在不损失精度的情况下，引入了cf选择技术，有效地减少了自由度。这些方法应用于碳原子的最低五重态，这是碳原子的激发态，但对化学键最重要。化学精确度是通过估计的精确能量的绝对解来实现的：所使用的cf的数量是4577，但是在利用cf选择技术来获得化学精确度之后减少到仅129。因此，如果所需的三电子和四电子积分是实际可用的，本理论可以实现精确的变分计算的多电子系统与紧凑的波函数。
The free complement-assisted() theory was developed as a variational method for solving the Schrödinger equations of atoms and molecules. This theory permits only a single correlatedterm in each complement function (cf) and the otherterms are replaced withterms so that the variational calculations are performed within one- to four-electron integrals. We developed the-extended Löwdin formula for the antisymmetrization of-included nonorthogonal functions and implemented one- to four-electron Slater atomic integral codes necessary for the present calculations. The cf selection technique was introduced to reduce the number of degrees of freedom efficiently without much loss of accuracy. These methods were applied to the lowest quintetstate of a carbon atom, which is an excited state of a carbon atom but most important for chemical bonds. The chemical accuracy was achieved with the absolute solution offrom the estimated exact energy: The number of the cf's used was 4577 but reduced to only 129 after utilizing the cf selection technique for obtaining the chemical accuracy. Thus, the present theory can realize accurate variational calculations of many-electron systems with compact wave functions if the required three- and four-electron integrals are practically available.