论文标题
基于双分歧原理
A state-specific multireference coupled-cluster method based on the bivariational principle
论文作者
论文摘要
提出了一种基于Arponen双分裂原理的州特异性多差群群集方法，即Bivar-MRCC方法。该方法基于单链式理论，因此具有相对简单的公式和适度的计算复杂性。与已建立的方法的主要区别在于双分裂配方，其中使波函数的独立参数（KET）及其复杂的共轭（BRA）。重要的是，这允许表现出乘法性可分离性（在该方法的扩展Bivar-Mrecc版本中精确，否则近似），同时保留工作方程的多项式缩放。双向原理的一个特征是形式的胸罩和KET参考可以作为双分性参数，这消除了对正式参考的许多偏见。描述了试点实施，并对几个标准问题进行了广泛的基准计算。 BIVAR-MRCC方法的结果与已建立的特异性多次多次方法相媲美。考虑到Bivar-MRCC方法的相对可负担性，它可能成为非专家的实用工具。
A state-specific multireference coupled-cluster method based on Arponen's bivariational principle is presented, the bivar-MRCC method. The method is based on singlereference theory, and therefore has a relatively straightforward formulation and modest computational complexity. The main difference from established methods is the bivariational formulation, in which independent parameterizations of the wavefunction (ket) and its complex conjugate (bra) are made. Importantly, this allows manifest multiplicative separability (exact in the extended bivar-MRECC version of the method, and approximate otherwise), while preserving polynomial scaling of the working equations. A feature of the bivariational principle is that the formal bra and ket references can be included as bivariational parameters, which eliminates much of the bias towards the formal reference. A pilot implementation is described, and extensive benchmark calculations on several standard problems are performed. The results from the bivar-MRCC method are comparable to established state-specific multireference methods. Considering the relative affordability of the bivar-MRCC method, it may become a practical tool for non-experts.
