Kiffner Martin, Jaksch Dieter, Ceresoli Davide
Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543, Singapore. Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom.
J Phys Condens Matter. 2018 Jul 11;30(27):275501. doi: 10.1088/1361-648X/aac85d. Epub 2018 May 29.
We show that efficient norm-conserving pseudopotentials for electronic structure calculations can be obtained from a polynomial Ansatz for the potential. Our pseudopotential is a polynomial of degree ten in the radial variable and fulfils the same smoothness conditions imposed by the Troullier-Martins method (TM) (1991 Phys. Rev. B 43 1993) where pseudopotentials are represented by a polynomial of degree twenty-two. We compare our method to the TM approach in electronic structure calculations for diamond and iron in the bcc structure and find that the two methods perform equally well in calculations of the total energy. However, first and second derivatives of the total energy with respect to atomic coordinates converge significantly faster with the plane wave cutoff if the standard TM potentials are replaced by the pseudopotentials introduced here.
我们表明，用于电子结构计算的高效规范守恒赝势可从势的多项式假设中获得。我们的赝势是径向变量的十次多项式，满足由特鲁利耶 - 马丁斯方法（TM）（1991年，《物理评论B》43卷，1993页）所施加的相同平滑条件，在该方法中赝势由二十二 次多项式表示。我们将我们的方法与TM方法在金刚石和体心立方结构铁的电子结构计算中进行比较，发现在总能量计算中这两种方法表现相当。然而，如果用这里引入的赝势取代标准的TM势，则总能量相对于原子坐标的一阶和二阶导数随着平面波截止显著更快地收敛。
