Search results for "sotropic nuclear magnetic shielding"
showing 2 items of 2 documents
From CCSD(T)/aug‐cc‐pVTZ‐J to CCSD(T) complete basis set limit isotropic nuclear magnetic shieldings via affordable DFT/CBS calculations
2011
It is shown that a linear correlation exists between nuclear shielding constants for nine small inorganic and organic molecules (N2, CO, CO2, NH3, CH4, C2H2, C2H4, C2H6 and C6H6) calculated with 47 methods (42 DFT methods, RHF, MP2, SOPPA, SOPPA(CCSD), CCSD(T)) and the aug‐cc‐pVTZ‐J basis set and corresponding complete basis set results, estimated from calculations with the family of polarization‐consistent pcS‐n basis sets. This implies that the remaining basis set error of the aug‐cc‐pVTZ‐J basis set is very similar in DFT and CCSD(T) calculations. As the aug‐cc‐pVTZ‐J basis set is significantly smaller, CCSD(T)/aug‐cc‐pVTZ‐J calculations allow in combination with affordable DFT/pcS‐n com…
Estimation of isotropic nuclear magnetic shieldings in the CCSD(T) and MP2 complete basis set limit using affordable correlation calculations
2013
A linear correlation between isotropic nuclear magnetic shielding constants for seven model molecules (CH2O, H2O, HF, F2, HCN, SiH4 and H2S) calculated with 37 methods (34 density functionals, RHF, MP2 and CCSD(T)), with affordable pcS-2 basis set and corresponding complete basis set results, estimated from calculations with the family of polarization-consistent pcS-n basis sets is reported. This dependence was also supported by inspection of profiles of deviation between CBS estimated nuclear shieldings and shieldings obtained with the significantly smaller basis sets pcS-2 and aug-cc-pVTZ-J for the selected set of 37 calculation methods. It was possible to formulate a practical approach o…