SYSTEMATIC STUDY OF THE STATIC ELECTRICAL PROPERTIES OF THE CO MOLECULE : INFLUENCE OF THE BASIS SET SIZE AND CORRELATION ENERGY
SYSTEMATIC STUDY OF THE STATIC ELECTRICAL PROPERTIES OF THE CO MOLECULE : INFLUENCE OF THE BASIS SET SIZE AND CORRELATION ENERGY
复制标题
分子静态电学性质的系统研究：基组尺寸和相关能的影响
DOI：
--
复制
发表时间：
1995
期刊：
影响因子：
--
通讯作者：
J. Andrés
中科院分区：
文献类型：
--
作者：
J. Luis;J. Martí;M. Duran;J. Andrés
基组的大小和相关能的CO分子的静电性能的影响进行评估。特别地，我们研究了核弛豫和振动对静态分子电学性质的贡献，振动斯塔克效应~VSE！振动强度效应~VIE！从数学的观点来看，当一个静态的和均匀的电场施加到一个分子上时，这个系统的能量可以用关于键长和场强的双幂级数来表示。从幂级数展开的势能，场依赖的表达式的平衡几何，势能和力常数得到。原子核弛豫和振动贡献的分子的电学性质进行了分析的衍生物的电子分子性质。在一般情况下，所提出的结果表明，需要准确地包含的相关能和大的基组来计算分子的电学性质和它们的衍生物相对于核位移或/和场强。相对于实验数据，SCF，CISD和QCISD方法计算的幂级数系数被高估。相反，扰动方法~MP2和MP4！倾向于低估他们。在平均和使用6- 3111 G（3 df）基组和CO分子，核弛豫和振动的贡献，分子的电学性质的金额的纯电子m，a，和B值的11.7%，3.3%和69.7%，分别。© 1995年美国物理研究所。
The influence of the basis set size and the correlation energy in the static electrical properties of the CO molecule is assessed. In particular, we have studied both the nuclear relaxation and the vibrational contributions to the static molecular electrical properties, the vibrational Stark effect ~VSE! and the vibrational intensity effect ~VIE!. From a mathematical point of view, when a static and uniform electric field is applied to a molecule, the energy of this system can be expressed in terms of a double power series with respect to the bond length and to the field strength. From the power series expansion of the potential energy, field-dependent expressions for the equilibrium geometry, for the potential energy and for the force constant are obtained. The nuclear relaxation and vibrational contributions to the molecular electrical properties are analyzed in terms of the derivatives of the electronic molecular properties. In general, the results presented show that accurate inclusion of the correlation energy and large basis sets are needed to calculate the molecular electrical properties and their derivatives with respect to either nuclear displacements or/and field strength. With respect to experimental data, the calculated power series coefficients are overestimated by the SCF, CISD, and QCISD methods. On the contrary, perturbation methods ~MP2 and MP4! tend to underestimate them. In average and using the 6-3111G(3 df ) basis set and for the CO molecule, the nuclear relaxation and the vibrational contributions to the molecular electrical properties amount to 11.7%, 3.3%, and 69.7% of the purely electronic m, a, and b values, respectively. © 1995 American Institute of Physics.