From CCSD(T)/aug-cc-pVTZ-J to CCSD(T) Complete Basis Set Limit Isotropic Nuclear Magnetic Shieldings via affordable DFT/CBS Calculations

TY - JOUR

T1 - From CCSD(T)/aug-cc-pVTZ-J to CCSD(T) Complete Basis Set Limit Isotropic Nuclear Magnetic Shieldings via affordable DFT/CBS Calculations

AU - Kupka, Teobald

AU - Stachow, Michal

AU - Nieradka, Marzena

AU - Kaminsky, Jakub

AU - Pluta, Tadeusz

AU - Sauer, Stephan P. A.

PY - 2011/5

Y1 - 2011/5

N2 - 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 C6H 6) 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 complete basis set calculations the prediction of nuclear shieldings at the CCSD(T) level of nearly similar accuracy as those, obtained by fitting results obtained from computationally demanding pcS-n calculations at the CCSD(T) limit. A significant saving of computational efforts can thus be achieved by scaling inexpensive CCSD(T)/aug-cc-pVTZ-J calculations of nuclear isotropic shieldings with affordable DFT complete basis set limit corrections.

AB - 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 C6H 6) 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 complete basis set calculations the prediction of nuclear shieldings at the CCSD(T) level of nearly similar accuracy as those, obtained by fitting results obtained from computationally demanding pcS-n calculations at the CCSD(T) limit. A significant saving of computational efforts can thus be achieved by scaling inexpensive CCSD(T)/aug-cc-pVTZ-J calculations of nuclear isotropic shieldings with affordable DFT complete basis set limit corrections.

KW - Faculty of Science

KW - NMR Spectroscopy

KW - Quantum Chemistry

KW - Theoretical Chemistry

KW - Scientific Computing

U2 - 10.1002/mrc.2738

DO - 10.1002/mrc.2738

M3 - Journal article

C2 - 21387405

SN - 0749-1581

VL - 49

SP - 231

EP - 236

JO - Magnetic Resonance in Chemistry

JF - Magnetic Resonance in Chemistry

IS - 4

ER -