Systematically convergent method for accurate total energy calculations with localized atomic orbitals
Systematically convergent method for accurate total energy calculations with localized atomic orbitals
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局域原子轨道精确总能量计算的系统收敛方法
DOI：
10.1103/physrevb.82.125112
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发表时间：
2010
影响因子：
3.7
通讯作者：
S. Sorella
中科院分区：
文献类型：
--
作者：
Sam Azadi;C. Cavazzoni;S. Sorella
我们介绍了一种求解局域原子轨道内自洽电子计算的方法，使我们能够以稳定、可控和系统的方式收敛到完全基集（CBS）极限。我们将我们的结果与用标准量子化学包得到的简单苯分子的结果进行了比较。我们找到了小基集的完美一致性，并证明了在我们的方案中，可以高效稳定地处理非常大的基。因此，我们可以避免引入任何外推来达到CBS极限。在我们的研究中，我们还使用由Slater行列式和Jastrow因子的乘积定义的标准多体波函数（WF）进行了变分蒙特卡罗（VMC）和晶格正则化扩散蒙特卡罗（LRDMC）。通过固定我们的新方案提供的Slater行列式对jasrow因子进行优化后，只有当原子轨道基足够大且接近CBS极限时，我们才能很好地描述苯分子的原子化能，从而得到最低的变分能。
We introduce a method for solving a self consistent electronic calculation within localized atomic orbitals, that allows us to converge to the complete basis set (CBS) limit in a stable, controlled, and systematic way. We compare our results with the ones obtained with a standard quantum chemistry package for the simple benzene molecule. We find perfect agreement for small basis set and show that, within our scheme, it is possible to work with a very large basis in an efficient and stable way. Therefore we can avoid to introduce any extrapolation to reach the CBS limit. In our study we have also carried out variational Monte Carlo (VMC) and lattice regularized diffusion Monte Carlo (LRDMC) with a standard many-body wave function (WF) defined by the product of a Slater determinant and a Jastrow factor. Once the Jastrow factor is optimized by keeping fixed the Slater determinant provided by our new scheme, we obtain a very good description of the atomization energy of the benzene molecule only when the basis of atomic orbitals is large enough and close to the CBS limit, yielding the lowest variational energies.