...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The journal of physical chemistry, A. Molecules, spectroscopy, kinetics, environment, & general theory >CASSCF/CAS-PT2 Study of Hole Transfer in Stacked DNA Nucleobases
【24h】

CASSCF/CAS-PT2 Study of Hole Transfer in Stacked DNA Nucleobases

机译：CASSCF / CAS-PT2在堆积的DNA核糖核酸酶中空穴转移的研究

获取原文
获取原文并翻译 | 示例
   

获取外文期刊封面封底 >>

       
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

CASSCF and CAS-PT2 calculations are performed for the ground and excited states of radical cations consisting of two and three nucleobases.The generalized Mulliken-Hush approach is employed for estimating electronic couplings for hole transfer in the pi-stacks.We compare the CASSCF results with data obtained within Koopmans'approximation.The calculations show that an excess charge in the ground and excited states in the systems is quite localized on a single base both at the CASSCF level and in Koopmans'picture.However,the CASSCF calculations point to a larger degree of localization and,in line with this,smaller transition dipole moments.The agreement between the CAS-PT2 corrected energy gaps and the values estimated with Koopmans'theorem is better,with the CAS-PT2 calculations giving somewhat smaller gaps.Overall,both factors result in smaller CASSCF/CAS-PT2 couplings,which are reduced by up to 40% of the couplings calculated using Koopmans'approximation.The tabulated data can be used as benchmark values for the electronic couplings of stacked nucleobases.For the base trimers,comparison of the results obtained within two-and three-state models show that the multistate treatment should be applied to derive reliable estimates.Finally,the superexchange approach to estimate the donor acceptor electronic coupling in the stacks GAG and GTG is considered.
机译：对由两个和三个核碱基组成的自由基阳离子的基态和激发态进行CASSCF和CAS-PT2计算，采用广义Mulliken-Hush方法估算pi堆中空穴传输的电子耦合，我们比较CASSCF结果计算结果表明，系统的基态和激发态中的多余电荷在CASSCF级别和Koopmans图片中都完全集中在一个单一的基上。然而，CASSCF计算指向一个总的来说，定位度越大，跃迁偶极矩就越小。CAS-PT2校正的能隙与用Koopmans定理估算的值之间的一致性更好，而CAS-PT2的计算得出的间隙要小一些。这两个因素都会导致较小的CASSCF / CAS-PT2耦合，最多可减少使用Koopmans逼近计算得出的耦合的40％。可以使用列表数据作为堆叠核碱基电子偶联的基准值。对于碱基三聚体，在两态和三态模型中获得的结果的比较表明，应采用多态处理来得出可靠的估计值。最后，用超级交换方法来估计考虑了堆叠体GAG和GTG中的供体受体电子耦合。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号