To confirm that these observations hold for other systems, we compared the CCSD total energies computed in single and double precision for the G2 set 37 using the the 6-31G(d), cc-pVDZ, cc-pVTZ, and cc-pVQZ basis sets. In addition, we compared single-precision results with those obtained with a cleanup step and with a calculation in which energy is computed in double precision using double-precision integrals and single-precision amplitudes. The results are summarized in Table . As one can see, the MAD in single-precision calculations is less than 4 J/mol. The MADs, STDs, and maximum errors in cc-pVQZ basis are only slightly larger than in cc-pVDZ.