Infinite-order diagrammatic summation approach to explicitly correlated congruent transformed Hamiltonian
| Autor: | Michael G. Bayne, John Drogo, Arindam Chakraborty |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
Physics
Chemical Physics (physics.chem-ph) Diagrammatic reasoning Pure mathematics Hamiltonian matrix Electronic correlation Computation Physics - Chemical Physics FOS: Physical sciences Mathematics::Metric Geometry Configuration interaction Atomic and Molecular Physics and Optics Hamiltonian (control theory) |
| Popis: | A resolution of identity approach to explicitly correlated congruent transformed Hamiltonian (CTH) is presented. One of the principle challenges associated with the congruent transformation of the many-electron Hamiltonian is the generation of three, four, five, and six particle operators. Successful application of the congruent transformation requires efficient implementation of the many-particle operators. In this work, we present the resolution of identity congruent transformed Hamiltonian (RI-CTH) method to handle many-particle operators. The resolution of identity was used to project the explicitly correlated operator in a N-particle finite basis to avoid explicit computation of the many-particle operators. Single-particle states were obtained by performing Hartee-Fock calculations, which were then used for construction of many-particle states. The limitation of the finite nature of the resolution of identity was addressed by developing partial infinite order (PIOS) diagrammatic summation technique. In the PIOS method, the matrix elements of the projected congruent transformed Hamiltonian was expressed in terms of diagrammatic notation and a subset of diagrams were summed up to infinite order. The RI-CTH and RI-CTH-PIOS methods were applied to isoelectronic series of 10-electron systems (Ne,HF,H2O,NH3,CH4) and results were compared with CISD and CCSD(T) calculations. One of the key results from this work is that for identical basis set, the RI-CTH-PIOS energies are lower than CISD and CCSD(T) values. 6 pages |
| Databáze: | OpenAIRE |
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