Twinning behavior of molecule-adapted Gaussian-type orbitals (GTOs) in cyclo-hydrocarbons

Authors

• TONG-HYOK CHA, Department of Structure Analysis, Central Institute of Experiment and Analysis, Pyongyang, DPR Korea; Department of Theoretical Chemistry, Faculty of Chemistry, University of Science, Pyongyang, DPR KoreaFollow
• GUM-CHOL KIM, Department of Structure Analysis, Central Institute of Experiment and Analysis, Pyongyang, DPR KoreaFollow
• KWANG-JIN RI, Department of Solid Physics, Faculty of Physics, University of Science, Pyongyang, DPR KoreaFollow
• JIN-NAM KIM, Department of Structure Analysis, Central Institute of Experiment and Analysis, Pyongyang, DPR KoreaFollow
• YONG-SU PAK, Department of Structure Analysis, Central Institute of Experiment and Analysis, Pyongyang, DPR KoreaFollow

Abstract

The saturated cyclo-hydrocarbons CnH2n (n = 3–7) were constructed by the iterative coupling of the structural unit groups (SUGs), specifically the SUG-CH2C2 fragment, which was previously established for molecular basis optimization. For the McLean–Chandler 6-311+G basis set, under the SUG perturbation, the outer (s′, p′) and diffuse (sʺ, pʺ) primitive Gaussian type orbitals for the core-atom C* of SUG-CH2C2 undergo an off-center spatial displacement into a twinning configuration. Specifically, the s-type twins (s′, sʺ) share identical Gaussian exponents and are symmetrically shifted toward the two neighboring carbon atoms, while the p-type twins (p′, pʺ) exhibit a matching configuration. Generally, this twinning behavior of floating primitives in molecule-adapted basis sets results in a lower total molecular energy.

Author ORCID Identifier

TONG-HYOK CHA: 0009-0000-4062-8490

GUM-CHOL KIM: 0009-0005-2285-946X

KWANG-JIN RI: 0009-0002-2603-2724

JIN-NAM KIM: 0000-0003-3617-4718

YONG-SU PAK: 0009-0000-1051-4679

DOI

10.55730/1300-0527.3911

Keywords

Gaussian basis set, Hartree-Fock method, perturbation, scale factor, floating shift

First Page

460

Last Page

466

Publisher

The Scientific and Technological Research Council of Türkiye (TÜBİTAK)

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Recommended Citation

CHA, T, KIM, G, RI, K, KIM, J, & PAK, Y (2026). Twinning behavior of molecule-adapted Gaussian-type orbitals (GTOs) in cyclo-hydrocarbons. Turkish Journal of Chemistry 50 (5): 460-466. https://doi.org/10.55730/1300-0527.3911