在CNDO/2和INDO模型中Hartree-Fock方法的Fortran 90实现
Fortran 90 implementation of the Hartree-Fock approach within the CNDO/2 and INDO models
摘要：
尽管原子和分子电子结构的从头算理论取得了巨大的进展，但它的应用仍然不可能用于非常大的系统。因此，基于零微分重叠（ZDO）方法的半经验模型哈密顿算子，如Pariser-Parr-Pople，CNDO，INDO等，为大型系统的从头计算提供了有吸引力的，计算上易于处理的替代方案。本文介绍了用CNDO/2和INDO方法求解分子体系的Hartree-Fock（HF）方程的Fortran 90程序。INDO方法可用于含有第一行原子的分子，而CNDO/2方法适用于同时含有第一行和第二行原子的分子。我们在开发代码时特别注意计算效率，因此，它使我们能够在几秒钟内在小型计算机上对C_60等大分子进行计算。除了能够计算分子轨道和总能量外，我们的代码还能够计算系统的电偶极矩，Mulliken布居分析和线性光学吸收光谱等特性。我们还演示了如何可以使用该程序来计算聚合物的每单位细胞的总能量。本文介绍的应用包括有机和无机小分子、富勒烯C_60和模型聚合物体系，即，含有交替的硼和氮原子（BN链）和碳原子（C链）的链。
英文摘要：
Despite the tremendous advances made by the ab initio theory of electronic structure of atoms and molecules, its applications are still not possible for very large systems. Therefore, semi-empirical model Hamiltonians based on the zero-differential overlap (ZDO) approach such as the Pariser-Parr-Pople, CNDO, INDO, etc. provide attractive, and computationally tractable, alternatives to the ab initio treatment of large systems. In this paper we describe a Fortran 90 computer program developed by us, that uses CNDO/2 and INDO methods to solve Hartree-Fock(HF) equation for molecular systems. The INDO method can be used for the molecules containing the first-row atoms, while the CNDO/2 method is applicable to those containing both the first-, and the second-row, atoms. We have paid particular attention to computational efficiency while developing the code, and, therefore, it allows us to perform calculations on large molecules such as C_60 on small computers within a matter of seconds. Besides being able to compute the molecular orbitals and total energies, our code is also able to compute properties such as the electric dipole moment, Mulliken population analysis, and linear optical absorption spectrum of the system. We also demonstrate how the program can be used to compute the total energy per unit cell of a polymer. The applications presented in this paper include small organic and inorganic molecules, fullerene C_60, and model polymeric systems, viz., chains containing alternating boron and nitrogen atoms (BN chain), and carbon atoms (C chain).
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
