Second-order Møller-Plesset perturbation energy obtained from divide-and-conquer Hartree-Fock density matrix

2006 ◽  
Vol 125 (20) ◽  
pp. 204106 ◽  
Author(s):  
Masato Kobayashi ◽  
Tomoko Akama ◽  
Hiromi Nakai
Keyword(s):  
Density Matrix ◽  
Second Order ◽  
Divide And Conquer ◽  
Hartree Fock ◽  
Perturbation Energy ◽  
Moller Plesset

Two‐level hierarchical parallelization of second‐order Møller–plesset perturbation calculations in divide‐and‐conquer method

2011 ◽  
Vol 32 (13) ◽  
pp. 2756-2764 ◽  
Author(s):  
Michio Katouda ◽  
Masato Kobayashi ◽  
Hiromi Nakai ◽  
Shigeru Nagase
Keyword(s):  
Second Order ◽  
Divide And Conquer ◽  
Moller Plesset

scholarly journals Energy-Based Automatic Determination of Buffer Region in the Divide-Andconquer Second-Order Møller-Plesset Perturbation Theory

2020 ◽  
Author(s):  
Toshikazu Fujimori ◽  
Masato Kobayashi ◽  
Tetsuya Taketsugu
Keyword(s):  
Correlation Energy ◽  
Atomic Orbital ◽  
Second Order ◽  
Divide And Conquer ◽  
Computational Time ◽  
Field Calculation ◽  
Automatic Determination ◽  
Energy Error ◽  
Buffer Region ◽  
Moller Plesset

In the linear-scaling divide-and-conquer (DC) electronic structure method, each subsystem is calculated together with the neighboring buffer region, the size of which affects the energy error introduced by the fragmentation in the DC method. The DC self-consistent field calculation utilizes a scheme to automatically determine the appropriate buffer region that is as compact as possible for reducing the computational time while maintaining acceptable accuracy (<i>J. Comput. Chem.</i> <b>2018</b>, <i>39</i>, 909). To extend the automatic determination scheme of the buffer region to the DC second-order Møller-Plesset perturbation (MP2) calculation, a scheme for estimating the subsystem MP2 correlation energy contribution from each atom in the buffer region is proposed. The estimation is based on the atomic orbital Laplace MP2 formalism. Based on this, an automatic buffer determination scheme for the DC-MP2 calculation is constructed and its performance for several types of systems is assessed.

scholarly journals Second Harmonic Generation, Electrooptical Pockels Effect, and Static First-Order Hyperpolarizabilities of 2,2′-Bithiophene Conformers: An HF, MP2, and DFT Theoretical Investigation

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Andrea Alparone
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Density Functional ◽  
Second Harmonic ◽  
Second Order ◽  
Pockels Effect ◽  
First Order ◽  
Hartree Fock ◽  
Electron Correlation Effects ◽  
Moller Plesset

The static and dynamic electronic (hyper)polarizabilities of the equilibrium conformations of 2,2′-bithiophene (anti-gauche and syn-gauche) were computed in the gas phase. The calculations were carried out using Hartree-Fock (HF), Møller-Plesset second-order perturbation theory (MP2), and density functional theory methods. The properties were evaluated for the second harmonic generation (SHG), and electrooptical Pockels effect (EOPE) nonlinear optical processes at the typical λ=1064 nm of the Nd:YAG laser. The anti-gauche form characterized by the S–C2–C2′–S dihedral angle of 137° (MP2/6-311G**) is the global minimum on the potential energy surface, whereas the syn-gauche rotamer (S–C2–C2′–S = 48°, MP2/6-311G**) lies ca. 0.5 kcal/mol above the anti-gauche form. The structural properties of the gauche structures are rather similar to each other. The MP2 electron correlation effects are dramatic for the first-order hyperpolarizabilities of the 2,2′-bithiophenes, decreasing the HF values by ca. a factor of three. When passing from the anti-gauche to the syn-gauche conformer, the static and frequency-dependent first-order hyperpolarizabilities increase by ca. a factor of two. Differently, the electronic polarizabilities and second-order hyperpolarizabilities of these rotamers are rather close to each other. The syn-gauche structure could be discriminated from the anti-gauche one through its much more intense SHG and EOPE signals.

Sign in / Sign up

Export Citation Format

Share Document