某些离解能、电子亲合能等的G2计算与评价

PoPle及其合作者创立的Gaussian再简称GZ）理论［‘－’］，以其相对可靠的化学精度和相应较小的计算量已经引起了实验和理论化学家们的广泛关注问．p。ple等人在他们的GZ文章中强调了GZ的理论计算结果在研究离解能等化学问题中与精确实验数据之间的偏差普遍不大于全8．狄J规厂‘．我们近期的研究表明＊’1，＊2和优（＊则在计算一般化学反应能量中，绝大多数情况下，分别都能保证结果与实验偏差在全8．4和士13kJ·mol‘以内．近年来，已有大量的研究工作表明，GZ的理论结果已广泛用于未知实验数据的预测、已有实验数据的评价和修正等…

G2(MP2), G2 Calculations and Assessment of the Atomization Energies, Electronic Affinities and lonization Potentials for Some Small Molecules

The atomization energies for BeF, BeF2, BF, BF2, BF3, BO, CF and CF2;electronic affinities for B, BO, CF, Li and LiF; ionization potentials(IP1) for BeF, BF2, BO,CF, CF2, CN, NO and NO2, IP2 for C, N and CF have been calculated at the G2(MP2) and G2 ab initio levels. These molecules are in their gaseous and ground electronic states with the temperature respect to 298K. The G2(MP2) results are compared with those of the G2 and the theoretical results are compared with those of the experiments as shown in Table 2 through Table 5. The G2(MP2) results for these 24 energies are in good agreement with those of the G2. Their deviations are within ±10kJ﹒mol-1 and the average absolute deviation is 3.2 kJ﹒mol-1. When compared with theories, the experimental results are in fairly agreement in most cases. For the larger deviations, we suppose that the experimental heat of formation for BeF is a little bit too low by about 10-20 kJ﹒mol-1, the electronic affinities for B, BO, CF and LiF are suggested to be re-examined, the experimental ionization potentials (IP1) for BeF, BF2 and CN are suggested to some further study and the IP2 for CF must be in error in the NBS Tables.