Su G L, Ning C G, Zhang S F, Ren X G, Zhou H, Li B, Huang F, Li G Q, Deng J K
Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China.
J Chem Phys. 2005 Feb 1;122(5):54301. doi: 10.1063/1.1839851.
The electron binding energy spectra and momentum profiles of the valence orbitals of difluoromethane, also known as HFC32 (HFC-hydrofluorocarbon) (CH(2)F(2)), have been studied by using a high resolution (e,2e) electron momentum spectrometer, at an impact energy of 1200 eV plus the binding energy, and by using symmetric noncoplanar kinematics. The experimental momentum profiles of the outer valence orbitals and 4a(1) inner valence orbital are compared with the theoretical momentum distributions calculated using Hartree-Fock and density functional theory (DFT) methods with various basis sets. In general, the shapes of the experimental momentum distributions are well described by both the Hartree-Fock and DFT calculations when large and diffuse basis sets are used. However, the result also shows that it is hard to choose the different calculations for some orbitals, including the methods and the size of the basis sets employed. The pole strength of the ionization peak from the 4a(1) inner valence orbital is estimated.
利用高分辨率（e,2e）电子动量谱仪，在1200 eV加上结合能的碰撞能量下，并采用对称非共面运动学，对二氟甲烷（也称为HFC32（氢氟碳化物）（CH(2)F(2)））价轨道的电子结合能谱和动量分布进行了研究。将外层价轨道和4a(1)内层价轨道的实验动量分布与使用Hartree-Fock和密度泛函理论（DFT）方法以及各种基组计算得到的理论动量分布进行了比较。一般来说，当使用大的弥散基组时，Hartree-Fock和DFT计算都能很好地描述实验动量分布的形状。然而，结果还表明，对于某些轨道，包括所采用的方法和基组大小，很难选择不同的计算方法。估计了来自4a(1)内层价轨道的电离峰的极强度。
