H_2O与NO,CN,OH自由基及负离子相互作用的CP研究

采用量子化学从头算方法在均衡（CounterPolse）校正和非校正势能面上研究 了珑O与NO，NO~-，CN，CNoH~-之间的相互作用比较了CP-梯度优化和非校正梯度优 化以及基组的选择对超分子结构和能量的影响．研究311++g**基组对于这些体系的 研究有很高的效率．这些自由基和负离子均能与H_2O形成强弱不同的氢强弱次序依 次为OH~-，CN，NO~_，OH，CN，NO，由相互作用能．△E~(CP)，成键临界点电荷密 E（2）分析均得到同样结果CF梯度优化和非校正梯度优化所得能量及正BSSE相差不 大。     

On the Importance of CP-corrected Gradient Optimization in the Study of Hydrogen Bonded Systems

Geometries, harmonic vibrational frequencies and interaction energies of the water-hydrogen sulfide dimer, hydrogen fluoride dimer and glycine zwitterion-water dimer were determined by the counterpoise-corrected (CP-corrected) gradient optimization that explicitly corrects for the basis set superpusition error (BSSE) and CP-uncorrected (normal) gradient opfimization respectively at the B3LYP and MP2 levels of theory, employing the popular Pople‘s standard 6-31G(d), 6-31G(d,p) and 6-311 G(d,p) basis sets in order to assess the importance of CP-corrected gradient optimiTation in the study of hydrogen bonded systems. The normal optimization of these three H-bonded systems obtained using these popular basis sets all yielded erratic results, whereas use of CP-corrected gradient optimization led to consistent results with those from larger basis sets. So this CP receipt becomes useful and necessary to correctly describe large systems, where the use of small basis sets may be necessary.     

H_2O与NO,CN,OH自由基及负离子相互作用的CP研究

采用量子化学从头算方法在均衡 (Counterpoise)校正和非校正势能面上研究了H2 O与NO ,NO-,CN ,CN-,OH ,OH-之间的相互作用 .比较了CP 梯度优化和非校正梯度优化以及基组的选择对超分子结构和能量的影响 .研究表明 ,6 311++g 基组对于这些体系的研究有很高的效率 .这些自由基和负离子均能与H2 O形成强弱不同的氢键 .按相互作用的强弱次序依次为OH-,CN-,NO-,OH ,CN ,NO ,由相互作用能ΔECP,成键临界点电荷密度 ρ ,二阶稳定化相互作用能E( 2 )分析均得到同样结果 .CP 梯度优化和非校正梯度优化所得能量及BSSE相差不大