排序方式: 共有12条查询结果,搜索用时 406 毫秒
1.
2.
运用包括非迭代三激发电子相关耦合簇CCSD(T)方法和Dunning等人使用的相关一致aug-CC-PVxZ(x=D,T,Q,5)自洽基组对XF(X=H,D,T)分子进行了结构优化,优化值然后被插值到CBS极限.结果表明随着x的增大aug-CC-PVxZ系列基组优化的结构逼近实验值,计算频率与实验值最大差距不足1%,最小仅为0.099%,平衡间距最大只有0.8%的差距.通过计算还表明:在结构优化和频率分析时CCSD(T)显示出优秀的特性,但在研究与边界态或解离有关的问题时,CCSD(T)不能给出良好的结果,相反CCSD方法却能给出合理的解离极限.最后我们研究了XF(X=H,D,T)的分子势能函数和光谱常数,理论结果与已知实验值吻合的非常好.首次获得了XF(X=H,D,T)系列分子的ω_ey_e,ω_eZ_e,β,γ,H_e,F_e值.Abstract: The equilibrium structure and vibrational frequency of FX(X=H,D,T)molecules are calculated at the CCSD(T)level in conjunction with serials of basis sets aug-CC-PVxZ(x=D,T,Q,5),and then the optimized values are extrapolated to CBS limitation.The theoretical results are shown to be in greater agreement with the experiments as x increases.The difference is only 1%between experiments and the Dresent calculation in vibrational frequency and the maximum equilibrium nuclear distance is 0.8%.Calculations indicate that CCSD(T)is the best method in the optimization and frequency analysis but it cannot give a correct limitation in the study of dissociation process whereas CCSD can solve this question and give a reasonable dissociation limitation.The analytic potential energy function of FX(X=H,D,T)is derived by least square fitting to Murrell-Sorbie and Dunham function,and the force constants and molecular constants are obtained.The results in this study are in good agreement with the experiment data.The ω_ey_e,ω_eZ_e,β,γ,H_e,F_e values are obtained for the first time. 相似文献
3.
4.
6.
7.
8.
9.
10.
长阳是一个老、少、边、贫的农村劳务人员输出大县,每年近10万人外出务工,大量耕地被抛荒闲置,森林资源得不到有效开发利用. 从2007年《农民专业合作社法》颁布实施后,返乡创业人员增加,各类专业合作社如雨后春笋般蓬勃发展,到2014年农民专业合作社达600多家,基本实现了村村有组织、产业全覆盖,发展数量位居宜昌市第一、湖北省前列. 2013年中央一号文件鼓励农民兴办家庭农场的政策出台后,长阳现已注册家庭农场105家,覆盖八镇三乡的多个产业,解决了农村大量的闲置土地资源,拓宽了农民的致富门路,增加了农民收入,也改变了传统农业刀耕火种的经营理念,推动了农村和农民面貌改变,在新农村建设中起到了引领和示范作用. 相似文献