共查询到20条相似文献,搜索用时 171 毫秒
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根据双原子谐振子模型近似,提出了估算分子晶体材料红外吸收边的理论方法,然后利用超分子量子化学从头算,计算了L-精氨酸一水磷酸盐(LAP)晶体和氘化L-精氨酸一水磷酸盐(d-LAP)晶体单元超分子的红外振动光谱,其中LAP晶体超分子计算值与晶体红外光谱实验值吻合,表明超分子计算能有效地模拟无机-有机杂化非线性光学晶体的红外振动光谱。在归属了超分子重要基频线后,分析其红外强度,并估算了泛频频率。根据我们提出的方法,估算了这两种晶体的红外吸收边,结果与实验值较吻合。表明我们建议的理论方法是合理的。此外,通过计算表明,如果非线性光学晶体材料的红外吸收边是由与活泼H有关的伸缩振动泛频频率决定,那么活泼H的氘化是一种改善红外吸收边的有效途径。 相似文献
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研究原子和双原子分子碰撞的振动激发过程,需要求争一组振动耦合微分方程组,给出了此方程组的一种数值求解方法,推导了IOS近似下的振动激发截面公式,将方程化简为无量纲形式,然后给出了解方程的方法,最后给出应用这种方法计算的一个例子,并与实验结果进行了比较。 相似文献
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双原子分子非谐振转波函数和能级 总被引:7,自引:3,他引:4
余春日 《原子与分子物理学报》2005,22(2):276-280
从双原子分子简谐势近似波函数出发,运用微扰理论计算出了双原子分子在非谐振转相互作用下的一级、二级近似能级和一级近似波函数. 相似文献
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代数方法(AM)的建立解决了实验方法和精确量子力学理论方法难以获得双原子分子的包含最高振动能级在内的所有高阶振动能级的精确数值这一问题.基于LeRoy与Bernstein的工作,孙卫国等又建立了精确计算双原子分子离解能的新解析表达式.应用新公式和代数方法(AM),研究了一些双原子分子部分电子态的振动能谱和分子离解能,获得了与实验值符合非常好的理论结果.该方法在理论上提供了获得双原子分子完全振动能谱和精确分子离解能的物理新方法. 相似文献
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Control of fundamental and overtone transitions of a vibration are studied for the diatomic molecule, HCl. Specifically, the results of the effect of variation of the penalty factor on the physical attributes of the system (i.e., probabilities) and pulse (i.e., amplitudes) considering three different pulse durations for each value of the penalty factor are shown and discussed. We have employed the optimal control theory to obtain infrared pulses for selective vibrational transitions. The optimization of initial guess field with Gaussian envelope, phrased as maximization of cost functional, is done using the conjugate gradient method. The interaction of the field with the molecule is treated within the semiclassical dipole approximation. The potential and the dipole moment functions used in the calculations of control dynamics are obtained from high level ab-initio calculations. 相似文献
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P.W. Abegg 《Molecular physics》2013,111(2):579-596
The spin-orbit coupling constants of a series of diatomic compounds containing first row atoms have been calculated using ab initio molecular wave functions with gaussian lobe and gaussian-type basis sets. In most cases, fair agreement with the experimental values has been achieved. It is pointed out that multicentre terms have almost no effect on the spin-orbit coupling constant. Furthermore, suggestions for a one-electron approximation using effective nuclear charges are presented. 相似文献
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Andrzej J. Sadlej 《Molecular physics》2013,111(4):593-604
The variation-perturbation method is applied to the calculation of the magnetic susceptibility of diatomic molecules within the basis of the CNDO/2 SCF wave functions. All the many-centre integrals which appear in the treatment were simplified according to the ZDO approximation. The calculated diamagnetic contribution is in good agreement with non-empirical results. It agrees also with available experimental data. Although the paramagnetic part of the susceptibility tensor was calculated with a simple two-term form of the variational correction, the results are comparable to those obtained in more advanced ab initio treatments. Also the computed total magnetic susceptibility of various diatomic molecules is in substantial agreement with non-empirical results. A comparison is made with the results of other semi-empirical calculations based on the CNDO/2 SCF wave functions. It follows that the results of the present method are remarkably better. 相似文献
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对煅硼砂饮片进行质量评价.以18个不同含水量的煅硼砂样品为研究对象,使用傅里叶红外光谱仪采集样品的红外吸收图谱,并对红外图谱进行分析,再根据分析结果对煅硼砂饮片进行质量评价.发现煅硼砂的红外光谱主要包括OH、BO3-3和BO5-4振动引起的三个吸收带,OH振动吸收带的位置及宽度依赖于含水量的高低,含水量越高,吸收带越宽... 相似文献
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在双原子分子核运动的波动方程中,计入分子的振转相互作用项,在Morse势近似下,得出的波函数除与振动量子数有关外,还与转动量子数有关。用该波函数编程计算了BN分子A3Π-X3Π辐射带系及BH分子A1Π-X1∑+带系的Franck-Condon因子。计算中转动量子数取值由J=0至J=180,结果适用于低温、高温和强激波条件。 相似文献
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We consider the soliton excitations in a diatomic chain with nonlinear on-site potential based on a quell-discreteness approximation, Different from the theoretical approach devel-oped before, our method is valid in the whole Brillouin zone of phonons. The gap solitons observed recently in a nonlinear diatomic pendulum lattice can be well explained qualita-tively. It is also shown that if the wave number of the carrier wave is near the edge of the Brillouin zone, the results coinside with that of Kivshar and Flytzanis about the gap solitons in diatomic lattices when the difference of mass between two kinds of atoms becomes small. 相似文献