The convergence of DFT‐computed interaction energies with increasing binding site model size was assessed. The data show that while accurate intercalator interaction energies can be derived from binding site models featuring only the flanking nucleotides for uncharged intercalators that bind parallel to the DNA base pairs, errors remain significant even when including distant nucleotides for intercalators that are charged, exhibit groove‐binding tails that engage in noncovalent interactions with distant nucleotides, or that bind perpendicular to the DNA base pairs. Consequently, binding site models that include at least three adjacent nucleotides are required to consistently predict converged binding energies. The computationally inexpensive HF‐3c method is shown to provide reliable interaction energies and can be routinely applied to such large models.

中文翻译：

---

模型大小在 DNA 嵌入的量子力学研究中的重要性

评估了 DFT 计算的相互作用能与增加的结合位点模型大小的收敛性。数据表明，虽然准确的嵌入剂相互作用能量可以从结合位点模型中得出，该模型仅具有与 DNA 碱基对平行结合的不带电嵌入剂的侧翼核苷酸，但即使包括带电嵌入剂的远距离核苷酸，显示出凹槽 - 误差仍然很大与远处核苷酸进行非共价相互作用的结合尾，或与 DNA 碱基对垂直结合的结合尾。因此，需要包含至少三个相邻核苷酸的结合位点模型来一致地预测会聚的结合能。