Hydrogen molecule in magnetic fields: The ground states of the Sigma manifold of the parallel configuration
Hydrogen molecule in magnetic fields: The ground states of the Sigma manifold of the parallel configuration
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DOI：
10.1103/physreva.56.1825
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发表时间：
1997-09-01
影响因子：
2.9
通讯作者：
Cederbaum, LS
中科院分区：
文献类型：
--
作者：
Detmer, T;Schmelcher, P;Cederbaum, LS
对平行构型下氢分子的电子结构进行了研究。研究了复盖从B=0到B=100A.U的宽场强范围的Sigma流形的基态，包括单重态和三重态。可以观察到各种有趣的现象。对于(1)Sigma(G)态，我们发现随着磁场强度的增加，平衡距离单调减小，解离能同时增大。(3)Sigma(G)状态被证明发展了一个在无场空间中没有对应的附加极小值。(1)Sigma(U)态的离解能呈单调增加，先增大后减小，核间距最小。对于这种状态，当磁场强度B大于或类似于20A.U时，解离通道为H-2--；H-+H+。这是由于强磁场中强束缚H态的存在。对于小于1.0A.U的磁场强度，排斥(3)Sigma(U)态有一个很浅的范德华极值。在我们计算的数值精度范围内。(1)Sigma(G)和(3)Sigma(U)态作为B的函数交叉，并且(3)Sigma(U)态是未结合态，在大于或类似于0.2A.U的磁场B中成为氢分子的基态。这对于白矮星附近分子氢的存在特别有意义。在超强场中，基态又是一个强束缚态，即(3)Pi(U)态。
The electronic structure of the hydrogen molecule is investigated for the parallel configuration. The ground states of the Sigma manifold are studied for ungerade and gerade parity as well as singlet and triplet states covering a broad regime of field strengths from B=0 up to B=100 a.u. A variety of interesting phenomena can be observed. For the (1) Sigma(g) state we found a monotonous decrease of the equilibrium distance and a simultaneous increase of the dissociation energy with growing magnetic-field strength. The (3) Sigma(g) state is shown to develop an additional minimum which has no counterpart in field-free space. The (1) Sigma(u) state shows a monotonous increase in the dissociation energy with a first increasing and then decreasing internuclear distance of the minimum. For this state the dissociation channel is H-2-->H-+H+ for magnetic field strengths B greater than or similar to 20 a.u. due to the existence of strongly bound H- states in strong magnetic fields. The repulsive (3) Sigma(u) state possesses a very shallow van der Waals minimum for magnetic-field strengths smaller than 1.0 a.u. within the numerical accuracy of our calculations. The (1) Sigma(g) and (3) Sigma(u) states cross as a function of B and the (3) Sigma(u) state, which is an unbound state, becomes the ground state of the hydrogen molecule in magnetic fields B greater than or similar to 0.2 a.u. This is of particular interest for the existence of molecular hydrogen in the vicinity of white dwarfs. In superstrong fields the ground state is again a strongly bound state, the (3) Pi(u) state.