B_nY(n=1—11)团簇的结构和电子性质

Structural and electronic properties of the B_nY(n= 1–11) clusters

利用密度泛函理论TPSSh方法对B采用6-311+G(d),对Y采用Lanl2dz相对论有效势基组,研究了BnY(n=1—11)团簇的平均结合能、二阶能量差分、最高分子占据轨道和最低空轨道之间的能级间隙、极化率和第一静态超极化率等物理化学性质.结果表明,随着尺寸的增大,BnY(n=1—11)团簇的最低能量结构从平面逐步演变为立体结构.随硼原子数n的增加,团簇的平均结合能表明了较好的热力学稳定性,有利于Y掺杂B团簇形成较大的块体材料.二阶能量差分表明基态B3Y,B5Y和B7Y团簇较相邻团簇稳定.能隙表明了基态B3Y,B5Y,B7Y和B9Y的化学稳定性较高.综合说明BnY(n=1—11)硼团簇中,基态B3Y,B5Y和B7Y具有较好的稳定性.极化率表明基态BnY团簇的电子结构随B原子的增加趋于紧凑,第一静态超极化率表明基态B5Y,B4Y,B3Y和B6Y平面结构的团簇具有明显的非线性光学性质,为寻找性能优异的非线性光学材料提供了一定的参考.

The geometric structures, electronic properties, average binding energies, second-order energy differences and energy gaps of BnY （n=1–11） clusters are systematically studied using the density functional theory （DFT） TPSSh method with 6-311＋G（d） basis set for B atoms and Lanl2dz relativistic effective core potential basis set for Y atom. It is found that with the size increasing, the lowest energy structures of BnY （n=1–11） clusters gradually evolve from planar shape to cubic structure. With the atoms of B increasing, the average binding energies of the ground state of BnY （n=1–11） clusters increase. The second-order energy differences and the energy gaps of the ground states of BnY （n = 1–11） clusters show that B3Y, B5Y and B7Y clusters possess relatively high stabilities. The polarization and the first static hyperpolarizability studied show that the plane structures of B5Y, B4Y, B3Y and B6Y clusters have larger nonlinear optical properties.