Schütz Martin, Werner Hans-Joachim, Lindh Roland, Manby Frederick R
Institut fur Theoretische Chemie, Universitat Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany.
J Chem Phys. 2004 Jul 8;121(2):737-50. doi: 10.1063/1.1760747.
An efficient method to compute analytical energy derivatives for local second-order Møller-Plesset perturbation energy is presented. Density fitting approximations are employed for all 4-index integrals and their derivatives. Using local fitting approximations, quadratic scaling with molecular size and cubic scaling with basis set size for a given molecule is achieved. The density fitting approximations have a negligible effect on the accuracy of optimized equilibrium structures or computed energy differences. The method can be applied to much larger molecules and basis sets than any previous second-order Møller-Plesset gradient program. The efficiency and accuracy of the method is demonstrated for a number of organic molecules as well as for molecular clusters. Examples of geometry optimizations for molecules with 100 atoms and over 2000 basis functions without symmetry are presented.
本文提出了一种计算局部二阶莫雷-普列斯特定理微扰能量解析能量导数的有效方法。对所有四中心积分及其导数采用密度拟合近似。通过使用局部拟合近似，实现了给定分子随分子大小的二次缩放以及随基组大小的三次缩放。密度拟合近似对优化平衡结构的准确性或计算的能量差影响可忽略不计。该方法可应用于比以往任何二阶莫雷-普列斯特定理梯度程序更大的分子和基组。通过多个有机分子以及分子簇证明了该方法的效率和准确性。给出了具有100个原子且无对称性且基函数超过2000个的分子几何优化实例。
