TY - JOUR
T1 - Linking the interatomic exchange-correlation energy to experimental J-coupling constants
AU - Alkorta, Ibon
AU - Popelier, Paul L. A.
PY - 2023/1/6
Y1 - 2023/1/6
N2 - The main aim of the current work is to find an experimental connection to the interatomic exchange-correlation energy as defined by the energy decomposition method Interacting Quantum Atoms (IQA). A suitable candidate as (essentially) experimental quantity is the NMR J-coupling constant denoted 3J(H,H’), which a number of previous studies showed to correlate well with QTAIM’s delocalisation index (DI), which is essentially a bond order. Inspired by Karplus equations, here we investigate correlations between 3J(H,H’) and a relevant dihedral angle in 6 simple initial compounds of the shape H3C-YHn (Y=C, N, O, Si, P and S), N-methylacetamide (as prototype of the peptide bond) and 5 peptide-capped amino acids (Gly, Ala, Val, Ile and Leu) because of the protein direction of the force field FFLUX. In conclusion, except for methanol, the inter-hydrogen exchange-correlation energy Vxc(H,H’) makes best contact with experiment, through 3J(H,H’), when multiplied with the internuclear distance RHH’.
AB - The main aim of the current work is to find an experimental connection to the interatomic exchange-correlation energy as defined by the energy decomposition method Interacting Quantum Atoms (IQA). A suitable candidate as (essentially) experimental quantity is the NMR J-coupling constant denoted 3J(H,H’), which a number of previous studies showed to correlate well with QTAIM’s delocalisation index (DI), which is essentially a bond order. Inspired by Karplus equations, here we investigate correlations between 3J(H,H’) and a relevant dihedral angle in 6 simple initial compounds of the shape H3C-YHn (Y=C, N, O, Si, P and S), N-methylacetamide (as prototype of the peptide bond) and 5 peptide-capped amino acids (Gly, Ala, Val, Ile and Leu) because of the protein direction of the force field FFLUX. In conclusion, except for methanol, the inter-hydrogen exchange-correlation energy Vxc(H,H’) makes best contact with experiment, through 3J(H,H’), when multiplied with the internuclear distance RHH’.
U2 - 10.1021/acs.jpca.2c07693
DO - 10.1021/acs.jpca.2c07693
M3 - Article
JO - The Journal of Physical Chemistry Part A: Molecules, Spectroscopy, Kinetics, Environment and General Theory
JF - The Journal of Physical Chemistry Part A: Molecules, Spectroscopy, Kinetics, Environment and General Theory
SN - 1089-5639
ER -