Accurate atomization energies from combining coupled-cluster computations with interference-corrected explicitly correlated second-order perturbation theory

作者：Vogiatzis Konstantinos D; Haunschild Robin; Klopper Wim^*

来源：Theoretical Chemistry Accounts, 2014, 133(3): 1446.

DOI：10.1007/s00214-014-1446-0

• Atomization energy
• Performance assessment
• Test set
• Coupled-cluster theory
• Explicit correlation
• Interference effects

Interference-corrected explicitly correlated second-order perturbation theory (INT-MP2-F12) is applied to accelerate the convergence to the complete-basis-set limit of coupled-cluster computations. Adding energy terms obtained from INT-MP2-F12 theory to the energies obtained from coupled-cluster singles-and-doubles (CCSD) computations yields a mean absolute deviation (MAD) from explicitly correlated CCSD results below 1 kJ/mol for a test set of 106 molecules. A composite scheme for the computation of atomization energies is assessed. This scheme is denoted as CCSD(T)+F12+INT and consists of the CCSD model with perturbative triples (CCSD(T)) supplemented with INT-MP2-F12 corrections, using a quadruple-zeta quality basis set (cc-pVQZ-F12). The composite scheme achieves chemical accuracy with respect to experimentally derived or computed reference values. Using Boys localized molecular orbitals, the MAD of the CCSD(T)+F12+INT/cc-pVQZ-F12 atomization energies from the reference values is below 1 kJ/mol for the G2/97 test set.

• 出版日期2014-1-30