Christopher Ingold Laboratory, Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K., and University Chemical Laboratory, Lensfield Road, Cambridge CB2 1EW, U.K.
J Chem Theory Comput. 2008 Mar;4(3):522-32. doi: 10.1021/ct700270d.
We compare two methods for estimating the induction energy in organic molecular crystals by approximating the charge density polarization in the crystalline state. The first is a distributed atomic polarizability model combined with distributed multipole moments, derived from ab initio monomer properties. The second uses an ab initio calculation of the molecular charge density in a point-charge field. Various parameters of the models, such as the rank of polarizability model, effect of self-consistent iterations, and damping, are investigated. The methods are applied to a range of observed and predicted crystal structures of three particularly challenging molecules, namely oxalyl dihydrazide, 3-azabicyclo[3,3,1]nonane-2,4-dione, and carbamazepine, as well as demonstrating the importance of induction in the naphthalene crystal. The two models agree well considering the different approximations made, and it is shown that the induction energy can be an important discriminator in the relative lattice energies of structures with substantially different hydrogen-bonding motifs.
我们比较了两种通过近似晶体中电荷密度极化来估算有机分子晶体诱导能的方法。第一种方法是一种结合了分布多极矩的分布式原子极化率模型，它是从单体的从头算性质中得到的。第二种方法使用点电荷场中分子电荷密度的从头算计算。我们研究了模型的各种参数，如极化率模型的阶数、自洽迭代的影响和阻尼。该方法应用于一系列观察到的和预测的三种特别具有挑战性的分子的晶体结构，即草酰二酰肼、3-氮杂双环[3.3.1]壬烷-2,4-二酮和卡马西平，同时还展示了诱导能在萘晶体中的重要性。考虑到所做的不同近似，这两种模型的结果非常吻合，并且表明在具有明显不同氢键模式的结构的相对晶格能中，诱导能可以是一个重要的判别因素。
