PHYS 542 |
| There has been much interest in cost-free improvements to second-order Moller-Plesset perturbation theory through the scaling of the same-spin and opposite-spin components of the correlation energy (spin component scaled MP2). By scaling the same-spin and opposite-spin components of the correlation energy from coupled cluster with single and double excitations, a similar result can be achieved. Optimal scaling parameters were determined to be 1.27 and 1.13 for the same-spin and opposite-spin scaling factors, respectively. These parameters were determined by optimizing the performance of SCS-CCSD for a set of 48 reaction energies. Preliminary results suggest that SCS-CCSD will outperform scaled MP2 methods for treating intermolecular interactions. Potential energy curves computed with SCS-CCSD for methane dimer and benzene dimer accurately predict the benchmark CCSD(T) potential curves. The performance of SCS-CCSD suggests that it is a reliable, lower cost alternative to CCSD(T). |
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PHYS Poster Session - General Theory
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster
Division of Physical Chemistry |