# 6.9.5 Examples

Example 6.23  Two jobs that compare the correlation energy calculated via the standard CCSD(T) method with the new CCSD(2) approximation, both using the frozen core approximation. This requires that CC_INCL_CORE_CORR must be specified as FALSE in the CCSD(2) input.

$molecule 0 2 O H O 0.97907$end

$rem METHOD ccsd(t) BASIS cc-pvtz N_FROZEN_CORE fc$end

@@@

$molecule read$end

$rem METHOD ccsd(2) BASIS cc-pvtz N_FROZEN_CORE fc CC_INCL_CORE_CORR false$end


Example 6.24  Using libpt for a standard CCSD(T) calculation

$molecule 0 2 O H O 0.97907$end

$rem METHOD ccsd(t) BASIS cc-pvtz N_FROZEN_CORE fc USE_LIBPT true$end