H ∕ D isotope effect on porphine and porphycene molecules with multicomponent hybrid density functional theory

Abstract

To analyze the H/D isotope effect on porphine and porphycene molecules including the protonic/deuteronic quantum nature and electron correlation efficiently, the authors have developed the new scheme of the multicomponent hybrid density functional theory [MC_(HF+DFT)]. The optimized geometries of porphine, porphycene, and these deuterated isotopomers by our MC_(HF+DFT) method are in good agreement with the experimental "high-symmetric" structures, contrary to the "low-symmetric" geometries optimized by pure multicomponent Hartree-Fock method. The optimized geometries for HD-porphine and HD-porphycene molecules, in which an inner hydrogen is replaced to a deuterium, are found to be low symmetric. Such drastic geometrical change induces the electronic polarization, and gives rise to the slight dipole moment values in these HD species. Their results clearly indicate that the difference of the nuclear quantum nature between inner proton and inner deuteron directly influences the molecular geometry and electronic structure.

Theoretical study on the mechanism of double proton transfer in porphycene by path-integral molecular dynamics simulations

“…1, which is showing the proton transfer pathways among the lowest four stationary points on the ground-state potential energy surface. All previous electronic structure calculations show that the C 2h trans structure is the most stable tautomer and that the energy of the C 2v cis structure is slightly higher than that of the trans structure [3][4][5][6][7][8][9][10][11][12][13][14]. Thus, the C 2v cis configuration is the intermediate on the potential energy surface.…”

MULTI-COMPONENT FIRST-PRINCIPLES CALCULATION ON ISOTOPE EFFECT IN HYDROGEN-BONDED DIELECTRIC MATERIALS K3H(SO4)2 AND K3D(SO4)2

“…On the other hand, we have proposed the multi-component molecular orbital (MC MO) methods [12][13][14], which can directly include the nuclear quantum effect. We have already reported the isotope effect of potassium dihydrogen phosphate (KDP) [15] using small cluster models with MC MO method.…”

Colle‐Salvetti‐type correction for electron–nucleus correlation in the nuclear orbital plus molecular orbital theory

“…Very recently, Udagawa and Tachikawa have proposed the formulation of the electron-nucleus correlation based on the CS functional. 30 In this study, we formulate and numerically assess a correction to the electron-nucleus interaction in the NOMO theory by using the CS-type correlation factor, 23 which permits us to effectively incorporate dynamical correlation, i.e., particle-particle collisions.…”