Inclusion of triples correction in the coupled cluster method

[摘要] The Coupled Cluster theory has proven itself as an effective method for the accurate calculations of correlation energy. A computational program for the full coupled-cluster model (CCSDT) single, double and triple excitation method has been integrated into the Gaussian program. This interface is based on original code that had been developed in late 80;;s. Single point energy calculations for the HF and OH- molecules verify the accuracy and stability of the newly developed code compared to the old one. Research on the potential energy curve of the MnO-4 anion has been conducted. Energy calculations for various Mn-O bond lengths using Hartree-Fock, MP2, MP3, MP4(SDQ), CCSDT), B3LYP, VSXC, PBE and CCSDT method exist. The CCSDT result is in excellent agreement with the experimental value of the Mn-O bond length.

[发布机构] Rice University