XF_3(X=N,P,As)价层电离势的运动方程耦合团簇理论计算

Theoretical calculation of valence shell ionization potentials of XF_3(X=N,P,As) using the equation-of-motion coupled cluster method

采用运动方程单双取代耦合团簇理论(EOM-CCSD)对XF3(X=N,P,As)的价层垂直离势(VIP)进行了系统计算,同时对称匹配团簇组态相互作用(SAC-CI)、外价层格林函数(OVGF)以及部分三阶近似(P3)方法也被应用到目前计算.与已有的实验结果比较表明EOM-CCSD计算的价层垂直电离势整体上与SAC-CI结果相近,而优于OVGF和P3理论结果,在整个价层上,EOM-CCSD结果与实验值总体差距约0.2eV,在外价层这种差距相对较小,在内价层则有所增大.随基组增大EOM-CCSD计算得到的第一电离势与实验值差距迅速减小,约0.03eV.根据SAC-CI,OVGF,P3和EOM-CCSD对NF3和PF3计算结果,判断AsF3第一电离势约为12.8eV,而非12.3eV,同时给出AsF3的价层电离势依次为12.64,15.23,16.30,17.37,18.05,21.98eV.

The equation-of-motion coupled cluster method with full inclusion of singles and doubles（EOM-CCSD） is applied to evaluate the vertical ionization potential（VIP） of XF3（X = N,P,As）.At the same time,symmetry adapted cluster configuration interaction（SAC-CI）,the outer valence shell Green function（OVGF） and partial third order approximation（P3） are also employed.Comparison with results of some experiments show average errors of 0.2 eV in the whole valence shell ionization region and are better than OVGF and P3 values and similar to the SAC-CI values.With the increase of basis set,the difference of the first VIP value between the EOM-CCSD and experimental becomes smaller and the different is about 0.03 eV.According to results from SAC-CI,OVGF,P3 and EOM-CCSD of NF3 and PF3,we can conclude that the first IP of AsF3 is not 12.3 eV but about 12.8 eV,the valence shell ionization potentials are 12.64,15.23,16.30,17.37,18.05 and 21.98 eV.