Quantum disorder in (NH4)2SnCl6: a quantum mechanical single-particle model interpretation of neutron diffraction data
Quantum disorder in (NH4)2SnCl6: a quantum mechanical single-particle model interpretation of neutron diffraction data
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DOI：
10.1088/0022-3719/17/23/009
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发表时间：
1984-08
期刊：
影响因子：
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通讯作者：
T. Brückel;W. Prandl;K. Vogt;C. Zeyen
中科院分区：
文献类型：
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作者：
T. Brückel;W. Prandl;K. Vogt;C. Zeyen
作者报告了一个直接测量的量子力学基态密度分布的三维旋转体（NH 4）在晶体旋转电位V（Ω）。本文分析了（NH_4）_2SnCl_6在T=6K时的中子布拉格散射数据，并将其展开成一系列的密度函数。这个系列中的系数以两种方式确定：（i）直接从实验数据和（ii）从单粒子哈密顿量的完全对角化。在后一种情况下，使用从文献中已知的三个电势V（ω）。他们发现，最近由两位作者（沃格特和Prandl，1983）从室温中子数据中用经典玻尔兹曼型方法导出的势提供了对6K测量的最佳拟合。没有一个势能完全再现其他作者所观察到的隧道分裂。
The authors report a direct measurement of the quantum mechanical ground-state density distribution of a 3D rotator (NH4) in a crystalline rotational potential V( omega ). Neutron Bragg scattering data of (NH4)2SnCl6 taken at T=6K are analysed in terms of a density distribution, which is expanded into a series of symmetry-adapted functions. The coefficients in this series are determined in two ways: (i) directly from the experimental data and (ii) from a complete diagonalisation of a single-particle Hamiltonian. In the latter case three potentials V( omega ) known from the literature are used. They find that the potential derived recently by two of the authors (Vogt and Prandl, 1983) from room-temperature neutron data with a classical Boltzmann-type approach provides the best fit to the 6K measurement. None of the potentials is able to reproduce completely the tunnel splitting observed by other authors.