CORE CORRELATION AND THE BINDING-ENERGY OF SC2
CORE CORRELATION AND THE BINDING-ENERGY OF SC2
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DOI：
10.1063/1.463173
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发表时间：
1992-08-01
影响因子：
4.4
通讯作者：
SIEGBAHN, PEM
中科院分区：
文献类型：
--
作者：
AKEBY, H;PETTERSSON, LGM;SIEGBAHN, PEM
Sc2 二聚体的解离能已使用多参考 CI 处理进行计算，并包括核心 (3p) 相关性的影响。 特别强调基组的收缩，以尽量减少原子相关能量损失和分子叠加误差。 核心 (3p) 相关性使 4s 轨道收缩，导致 4s 和 3d 轨道的径向范围之间的比率减小。 这会导致键合距离缩短（减少 0.20 a0）并改善 3d-3d 重叠。 通过核心关联，结合能增加了0.11 eV。 最终获得的 D(e) 为 0.77 eV（1.1 +/- 0.2 eV 扩展）。提出了核极化势形式的扩展，包括场梯度和四极核极化率，并与原子和 Sc2 的显式核相关结果进行了比较。
The dissociation energy of the Sc2 dimer has been computed using a multireference CI treatment and including the effects of core (3p) correlation. Special emphasis has been put on the contraction of the basis set to minimize atomic correlation energy loss and molecular superposition errors. Core (3p) correlation gives a contraction of the 4s orbital resulting in a reduced ratio between the radial extents of the 4s and 3d orbitals. This results in a decreased bond distance (by 0.20 a0) and improved 3d-3d overlap. The binding energy is increased by 0.11 eV through core correlation. The finally obtained D(e) is 0.77 eV (1.1 +/- 0.2 eV expt.) An extension of the core-polarization potential formalism to include field-gradients and quadrupole core polarizabilities is presented and compared with the results of explicit core correlation for both the atom and Sc2.