Toward an accurate and efficient theory of physisorption. I. Development of an augmented density-functional theory model.
Toward an accurate and efficient theory of physisorption. I. Development of an augmented density-functional theory model.
复制标题
建立准确有效的物理吸附理论。
DOI：
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发表时间：
2008
影响因子：
2.9
通讯作者：
G. Scoles
中科院分区：
文献类型：
--
作者：
G. Murdachaew;Stefano de Gironcoli;G. Scoles
目前可用的密度泛函无法描述弱结合复合物中存在的相互作用能的色散分量。此外，从密度泛函理论得到的交换能往往是不正确的。有问题的例子包括货车德瓦尔斯束缚的稀有气体原子簇和大多数氢键分子系统。因此，准确的从头计算方法来处理分子间的力量，应在这样的系统中使用。然而，这些方法太慢，不适用于模拟吸附所需的大型系统。这就是为什么DFT继续被使用的原因，此外，一个非常常见的误差补偿有时会产生与相应实验数据的某种一致性。本文详细分析了标准密度泛函理论在描述稀有气体-稀有气体、金属原子-稀有气体、金属原子-金属原子二聚体弱束缚方面的不足，受Hartree-Fock加（阻尼）色散（HFD）方法成功的启发，我们测试了一种改进的混合模型的使用，其中密度泛函相互作用能（经校正的汇率和避免重复计算离散），与精确的理论或实验基准比较表明，我们的DFdD方法使用revPBEx或revPBEx+ VWNc泛函和准确的色散系数被发现恢复的相互作用能曲线非常好的许多测试系统。本系列的第二节和第三节将描述使用DFdD方法对先前研究得很好（但尚未解决）的Cu 2 +/Cu（111）进行物理吸附。
Currently available density functionals cannot describe the dispersion component of the interaction energy present in weakly bound complexes. Moreover, the exchange energy as obtained from the density-functional theory is often incorrect. Examples of problematic cases include clusters of van der Waals-bound rare-gas atoms and most hydrogen-bonded molecular systems. Thus, accurate ab initio methods to treat intermolecular forces should be used in such systems. These methods are, however, too slow to be applicable to the large systems needed to model adsorption. This is why DFT continues to be used, where, in addition, a quite common compensation of errors sometimes produces some sort of agreement with the corresponding experimental data. In this paper, we analyze in detail the inadequacy of standard DFT for describing the weak binding present in a few rare gas-rare gas, metal atom-rare gas, and metal atom-metal atom dimers.Inspired by the success of the Hartree-Fock plus (damped) dispersion (HFD) method, we test the use of an improved hybrid model in which to a density-functional interaction energy (with corrected exchange and avoidance of double-counting of dispersion), a (damped) dispersion expansion is added in the usual way.Comparisons with accurate theoretical or experimental benchmarks show that our DFdD method using the revPBEx or revPBEx+VWNc functionals and accurate dispersion coefficients is found to recover the interaction energy curves very well for many of the tested systems. The sec and paper in this series will describe the use of the DFdD method for physisorption for the previously well-studied (but not solved) case of Xe/Cu(111).