Binding energy of the ring form of (H2O)6: Comparison of the predictions of conventional and localized‐orbital MP2 calculations
Binding energy of the ring form of (H2O)6: Comparison of the predictions of conventional and localized‐orbital MP2 calculations
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DOI：
10.1063/1.472910
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发表时间：
1996-12
影响因子：
4.4
通讯作者：
J. Pedulla;F. Vila;K. Jordan
中科院分区：
文献类型：
--
作者：
J. Pedulla;F. Vila;K. Jordan
用MP2和定域轨道MP2(LMP2)方法计算了(H2O)6的环型结合能。结果表明，LMP2方法能有效地减小基组叠加误差对结合能的贡献。O原子上的f和g函数以及H原子上的d和f函数的加入使(H2O)6环的稳定性增加了约3.2kcal/m o l。我们估算的最佳结合能为−44.3kcal/m o l。其中，三体相互作用贡献了−11.60千卡/摩尔，四体、五体和六体相互作用共同贡献了−2.0千卡/摩尔。虽然包含电子关联能对于获得准确的二体相互作用是至关重要的，但电子关联对三体和更高的体相互作用的净影响仅约为0.2kcal/mol。基于这些结果，提出了一种计算高效的策略来获得精确的氢键团簇的结合能。
The binding energy of the ring form of (H2O)6 is calculated by means of the MP2 and localized‐orbital MP2 (LMP2) methods. The LMP2 method is found to be effective at reducing basis set superposition error in the electron correlation contribution to the binding energy. The inclusion of f and g functions on the O atoms and d and f functions on the H atoms leads to an increase of about 3.2 kcal/mol in the stability of the ring form of (H2O)6. Our best estimate of the binding energy is −44.3 kcal/mol. Of this, three‐body interactions contribute −11.60 kcal/mol, and the four‐ , five‐ , and six‐body interactions combined contribute −2.0 kcal/mol. Although inclusion of electron correlation energy is crucial for obtaining an accurate value of the two‐body interactions, the net effect of electron correlation on the three‐ and higher‐body interactions is only about 0.2 kcal/mol. Based on these results, a computationally efficient strategy for obtaining accurate binding energies of hydrogen‐bonded clusters is proposed.