Sillaste Spencer, Thompson Russell B
Department of Physics & Astronomy and Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1.
J Phys Chem A. 2022 Jan 20;126(2):325-332. doi: 10.1021/acs.jpca.1c07128. Epub 2022 Jan 7.
A density functional theory based on polymer self-consistent field theory is applied to systems of two atoms in order to show that this approach is capable of predicted molecular bonding. Periodic table elements from hydrogen up to neon are examined and homonuclear diatomic molecules are found to form for H, N, O, and F, in agreement with known results. The heteronuclear molecules CO and HF, which are known to exist under ambient conditions, are also found to be stable. Bond lengths for most of these molecules agree with experimental results to within less than 8%, with the exception of O and F which deviate more significantly. The bonding energy for H is given and is within 16% of the known value, but fundamental vibrational frequencies do not agree well with experiment. The main approximations of the theory are very simple and include a Fermi-Amaldi correction to the electron-electron interaction to account for self-interactions and a basic expression for the Pauli potential to account for the exclusion principle. The self-consistent equations are solved in terms of basis functions that encode the cylindrical symmetry of diatomic molecules. Since orbitals are not used, the approach is related to orbital-free density functional theory.
一种基于聚合物自洽场理论的密度泛函理论被应用于双原子体系，以表明这种方法能够预测分子键合。研究了从氢到氖的周期表元素，发现H、N、O和F形成了同核双原子分子，这与已知结果一致。已知在环境条件下存在的异核分子CO和HF也被发现是稳定的。这些分子中大多数的键长与实验结果的吻合度在8%以内，但O和F的偏差更为显著。给出了H的键能，其在已知值的16%以内，但基本振动频率与实验结果不太吻合。该理论的主要近似非常简单，包括对电子-电子相互作用的费米-阿玛尔迪修正以考虑自相互作用，以及对泡利势的基本表达式以考虑泡利不相容原理。自洽方程是根据编码双原子分子圆柱对称性的基函数求解的。由于未使用轨道，该方法与无轨道密度泛函理论相关。
