排序方式: 共有127条查询结果,搜索用时 15 毫秒
31.
运用密度泛函B3P86方法和cc-PV5Z基组,获得了BH分子基态在不同外电场下的键长、偶极矩和振动频率等物理性质参数.通过分析物理性质参数,判断离解电场所处的范围,设置合适的参数扫描该范围的单点能获得势能曲线.结果表明物理性质参数和势能值随外电场的变化而变化,特别是在反向电场中.利用Morse势模型拟合无外场下势能函数,得到的拟合参数与实验值吻合较好,采用偶极近似构建外电场下的势能函数模型,编制程序拟合对应的势能函数,得出拟合参数,再计算临界离解电场参量,结果与数值计算值较为一致,说明构建的模型是可靠和准确的.为分析外场下分子光谱、动力学特性和分子Stark效应冷却囚禁提供理论参考. 相似文献
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采用乘积近似法构建配分函数合理模型,计算了SO2分子的总配分函数.利用所得的配分函数、将常温下的无转动跃迁矩平方近似为一常数并应用于高温及Herman-Wallis因子系数,编制光谱程序,计算了烟道气体SO2分子三个主要跃迁带100-000、001-000和101-000不同温度段的光谱强度和吸收系数.结果表明,计算所得的配分函数和谱线强度与数据库相比,不管是常温296 K还是高温3000 K,都吻合较好,相对偏差都在3%以下,这说明构建的配分函数模型和编制的程序是可靠的,在此基础上,进一步计算了各跃迁带在不同温度的吸收系数.从模拟光谱图可看出,强度随着温度升高明显减小,谱带带心没变,峰值波数向两边偏移;吸收系数随着温度升高也减少,其中在3000 K以下吸收峰位置增宽,到高达4000 K以上基本不再变换,这为监测烟道气体环境污染提供实验和理论参考. 相似文献
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应用群论及原子分子反应静力学方法推导了SiO2分子的电子态及其离解极限,采用B3P86方法,在6-311G**水平上,优化出SiO2基态分子稳定构型为单重态的C2V构型,其平衡核间距Re=RSi—O=0.1587 nm,∠OSiO=111.2°,能量为-440.4392 a.u..同时计算出基态的简正振动频率:对称伸缩振动频率ν(B2)=945.4cm-1,弯曲振动频率ν(A1)=273.5 cm-1和反对称伸缩振动频率ν(A1)=1362.9cm-1.在此基础上,使用多体项展式理论方法,导出了基态SiO2分子的全空间解析势能函数,该势能函数准确再现了SiO2(C2V)平衡结构. 相似文献
34.
利用密度泛函理论研究B6和LimB6 (m= 1–2)团簇的结构及其储氢性能. 结果表明, 氢分子在B6团簇的三种可能结构中均发生解离吸附, Li原子在B6团簇表面不发生团聚,每一个Li原子均吸附几个氢分子. 其中以两个Li原子修饰笼形B6团簇吸附完整氢分子数最多,储氢质量分数为20.38%, 氢分子的平均吸附能为1.683 kcal/mol,表明了它在常温常压条件下作为储氢材料的可行性.
关键词:
mB6 (m=1-2)团簇')" href="#">LimB6 (m=1-2)团簇
密度泛函理论(DFT)
吸附能
储氢性能 相似文献
35.
Configuration interaction calculations on the spectroscopic and transition properties of magnesium chloride 下载免费PDF全文
The potential energy curves(PECs) of 14 Λ–S states for magnesium chloride(Mg Cl) have been calculated by using multi-reference configuration interaction method with Davidson correction(MRCI + Q). The core-valence correlation(CV), scalar relativistic effect, and spin–orbit coupling(SOC) effect are considered in the electronic structure computations.The spectroscopic constants of X~2Σ~+ and A ~2Π states have been obtained, which are in good agreement with the existing theoretical and experimental results. Furthermore, other higher electronic states are also characterized. The permanent dipole moments(PDMs) of Λ–S states and the spinorbit(SO) matrix elements between Λ–S states are also computed. The results indicate that the abrupt changes of PDMs and the SO matrix elements are attributed to the avoided crossing between the states with the same symmetry. The SOC effect is taken into account with Breit–Pauli operator, which makes the 14Λ–S states split into 30 ? states, and leads to a double-well potential of the ? =(3)1/2 state. The energy splitting for the A2Π is calculated to be 53.61 cm~(-1) and in good agreement with the experimental result 54.47 cm~(-1). The transition dipole moments(TDMs), Franck–Condon factors(FCFs), and the corresponding radiative lifetimes of the selected transitions from excited ? states to the ground state X~2Σ + 1/2 have been reported. The computed radiative lifetimes τν of low-lying excites ? states are all on the order of 10 ns. Finally, the feasibility of laser cooling of Mg Cl molecule has been analyzed. 相似文献
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BH分子X1∑+、A1∏和B1∑+态的势能函数 总被引:2,自引:0,他引:2
利用SAC/SAC-CI方法,使用D95++、6-311++g及cc-PVTZ等基组,对BH分子的基态(X1∑+)、第一简并激发态(A1∏)及第二激发态(B1∑+)的平衡结构和谐振频率进行了优化计算.通过对三个基组计算结果的比较,得出了cc-PVTZ基组为三个基组中的最优基组的结论;使用cc-PVTZ基组,利用SAC的GSUM(group sum ofoperators)方法对基态(X1∑+),SAC-CI的GSUM方法对激发态(A1∏和B1∑+)进行单点能扫描计算,用正规方程组拟合Murrell-Sorbie函数,得到了相应电子态的完整势能函数;从得到的势能函数计算了与基态(X1∑+)、第一简并的激发态(A1∏)和第二激发态(B1∑+)相对应的光谱常数(Be、αe、ωe和ωeXe),结果与实验数据较为一致.其中基态、第一激发态与实验数据吻合得较好. 相似文献
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利用SAC/SAC—CI方法,使用D95(d)、6-311G**及CC—PVTZ等基组,对LiH分子的基态(X^1∑^+)、第一激发态(A^1∑^+)及第二简并激发态(B^1П)的平衡结构和谐振频率进行了优化计算.通过对三个基组的计算结果的比较,得出了D95(d)基组为三个基组中的最优基组的结论;使用D95(d)基组,利用SAC的GSUM(Group Sum of Operators)方法对基态(X^1∑^+)、SAC—CI的GSUM方法对激发态(A^1∑^+和B ^1П)进行单点能扫描计算,用正规方程组拟合Murrell—Sorbie函数,得到了相应电子态的完整势能函数;从得到的势能函数计算了与基态(X ^1∑^+)相对应的光谱常数,结果与实验数据较为一致. 相似文献
40.
The structures and hydrogen storage properties of sodium atoms decorated B6 clusters are investigated by the B3LYP method with a 6-311+G (d, p) basis set. For NamB6 (m = 1-3) clusters, Na atoms are always inclined to separate far enough from each other and not cluster together on a B6 cluster surface so that each Na atom has sufficient space to bind hydrogen molecules. The hydrogen storage gravimetric density of a two Na atoms decorated B6 cluster is 17.91 wt% with an adsorption energy per H2 molecule (AAE/H2) of 0.6851 kcal.mo1^-1. The appropriate AAE/H2 and preferable gravimetric density of the two Na atoms decorated B6 cluster complex indicate that it is feasible for hydrogen storage application in ambient conditions. 相似文献