Analytical energy gradient in variational calculations of the two lowest P3 states of the carbon atom with explicitly correlated Gaussian basis functions
Analytical energy gradient in variational calculations of the two lowest P3 states of the carbon atom with explicitly correlated Gaussian basis functions
复制标题
具有明确相关高斯基函数的碳原子两个最低 P3 态变分计算中的解析能量梯度
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
L. Adamowicz
中科院分区：
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作者：
K. Sharkey;S. Bubin;L. Adamowicz
原子和分子系统的基态和激发态的变分计算，明确地依赖于粒子间的距离的基函数，可以产生非常准确的结果，提供的基函数参数是彻底优化的能量最小化。在这项工作中，我们推导出的算法的能量梯度确定相对于非线性指数参数的显关联高斯函数用于计算n电子原子系统的两个p-电子和（n-2）s-电子。我们所使用的原子哈密顿量是通过严格地从实验室框架哈密顿量中分离出质心运动的动能而获得的，并且明确地取决于原子核的有限质量。在能量的变分最小化中具有梯度的优点在碳原子的基态和第一激发P3态的计算中被证明。对于前者，洛…
Variational calculations of ground and excited bound states on atomic and molecular systems performed with basis functions that explicitly depend on the interparticle distances can generate very accurate results provided that the basis function parameters are thoroughly optimized by the minimization of the energy. In this work we have derived the algorithm for the gradient of the energy determined with respect to the nonlinear exponential parameters of explicitly correlated Gaussian functions used in calculating n-electron atomic systems with two p-electrons and (n−2) s-electrons. The atomic Hamiltonian we used was obtained by rigorously separating out the kinetic energy of the center of mass motion from the laboratory-frame Hamiltonian and explicitly depends on the finite mass of the nucleus. The advantage of having the gradient available in the variational minimization of the energy is demonstrated in the calculations of the ground and the first excited P3 state of the carbon atom. For the former the lo...