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Electronic structures and related properties of a defective endohedral metallofullerene U-2@C-61-Def[5, 6] are studied using density functional theory. It is shown that unlike the U-2@C-61-Def[6, 6] which has a nonet ground state, the U-2@C-61-Def[5, 6] has a quintet ground spin state with a lower total energy than the U-2@C-61-Def[6, 6]. This is due to the antiferromagnetic coupling of the net spin electrons of the U-2 unit with the net spin of both the cage and the adatom. Compared with the U-2@C-60, the [5, 6]-type defect demonstrates almost no change in the energy gap, while the [6, 6]-type defect does show a reduction. The electronic states and energy gaps of the endohedral metallofullerenes can therefore be engineered in a controllable manner by introducing different adatom-type defects. (C) 2014 Elsevier Ltd. All rights reserved. |
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