TY - JOUR

T1 - Three Methods to Identify and Visualize Nonuniform Changes in Interatomic Interactions: Second-Difference Analysis, Anharmonicity Inversion, and Distance-Dependent NMR Absolute Shieldings

AU - Shenderovich, IG

AU - Denisov, GS

N1 - Times Cited in Web of Science Core Collection: 0 Total Times Cited: 0 Cited Reference Count: 53

PY - 2026/3/31

Y1 - 2026/3/31

N2 - Vibrational excitation of chemical bonds induces nonuniform distortions in the potential energy surface that reflect changes in interatomic interactions. These qualitative changes can be identified and visualized using three complementary methods. The second-difference analysis, tracking successive vibrational energy gaps, applies when all vibrational level energies and the dissociation limit are known. The anharmonicity-inversion method uses a Morse potential and requires only the vibrational energy gaps 0 -> 1 and 1 -> 2, along with the dissociation limit, to reveal anomalous local anharmonicity near the first excited vibrational level by comparing the Morse-predicted bond energy with the true bond energy. Finally, NMR shielding-tensor mapping permits identification of interatomic distances at which the electronic environment undergoes qualitative changes, without requiring prior knowledge of the potential. Applied to the diatomic cations C+-Ng and H+-Ng (Ng = He, Ne, and Ar), all three approaches consistently delineate specific vibrational-state or internuclear distance regions where the character of the interatomic interaction changes noticeably.

AB - Vibrational excitation of chemical bonds induces nonuniform distortions in the potential energy surface that reflect changes in interatomic interactions. These qualitative changes can be identified and visualized using three complementary methods. The second-difference analysis, tracking successive vibrational energy gaps, applies when all vibrational level energies and the dissociation limit are known. The anharmonicity-inversion method uses a Morse potential and requires only the vibrational energy gaps 0 -> 1 and 1 -> 2, along with the dissociation limit, to reveal anomalous local anharmonicity near the first excited vibrational level by comparing the Morse-predicted bond energy with the true bond energy. Finally, NMR shielding-tensor mapping permits identification of interatomic distances at which the electronic environment undergoes qualitative changes, without requiring prior knowledge of the potential. Applied to the diatomic cations C+-Ng and H+-Ng (Ng = He, Ne, and Ar), all three approaches consistently delineate specific vibrational-state or internuclear distance regions where the character of the interatomic interaction changes noticeably.

KW - anharmonicity

KW - dissociation energy

KW - Morse potential

KW - potential energy surface

KW - protonated inert gases

KW - scalar coupling

KW - term approximation

KW - NOBLE-GAS HYDRIDES

KW - HYDROGEN-BONDS

KW - SPECTROSCOPY

KW - PYRIDINE

KW - STATES

KW - SHIFT

KW - NEH+

KW - N-15

UR - https://www.mendeley.com/catalogue/3e0bf435-d5eb-3dbe-b54f-122493e55396/

U2 - 10.1002/qua.70184

DO - 10.1002/qua.70184

M3 - статья

VL - 126

JO - International Journal of Quantum Chemistry

JF - International Journal of Quantum Chemistry

SN - 0020-7608

IS - 7

ER -