Theoretical study of the H/D isotope effect on phase transition of hydrogen-bonded organic conductor κ-H3(Cat-EDT-TTF)2

2016 ◽  
Vol 18 (43) ◽  
pp. 29673-29680 ◽  
Author(s):  
Kaichi Yamamoto ◽  
Yusuke Kanematsu ◽  
Umpei Nagashima ◽  
Akira Ueda ◽  
Hatsumi Mori ◽  
...  
Keyword(s):  
Phase Transition ◽  
Isotope Effect ◽  
Theoretical Study ◽  
Electron System ◽  
Organic Conductor ◽  
Single Well ◽  
Hydrogen Bonded

κ-H3(Cat-EDT-TTF)2 (H-TTF) is a hydrogen-bonded π-electron system. Only its isotopologue, D-TTF, shows the phase transition. We obtained a symmetric single-well effective-PEC for H-TTF and low-barrier effective-PEC for D-TTF.

Theoretical Study on the Phase Transition and the H/D Isotope Effect of Squaric Acid

2012 ◽  
Vol 189 ◽  
pp. 169-177 ◽  
Author(s):  
Takayoshi Ishimoto ◽  
Masanori Tachikawa
Keyword(s):  
Phase Transition ◽  
Isotope Effect ◽  
First Principles ◽  
Dielectric Material ◽  
Dielectric Materials ◽  
First Principles Calculation ◽  
Squaric Acid ◽  
Teller Distortion ◽  
Unit Structure ◽  
Hydrogen Bonded

We investigated the phase transition and the isotope effect in squaric acid (H2C4O4, abbreviated H2SQ), a hydrogen-bonded dielectric material. Using first-principles calculation, we found that Jahn-Teller distortion of the unit structure (C4H4O4) was the major driving force for the phase transition in the H2SQ crystal. In order to elucidate the isotope effect on the phase transition in deuterated squaric acid (D2SQ), we employed the multi-component molecular orbital (MC_MO) method, which directly takes into account the quantum effects of protons and deuterons. Using this model, we successfully predicted the difference between the phase transition temperature of H2SQ and that of D2SQ to be 192K, which is in reasonable agreement with the experimental value of 145 K. We found that the isotope effect in the H2SQ/D2SQ system was based more on shrinking distribution of the deuteron wave rather than that of the proton wave. When the MC_MO method was coupled with adequate cluster models, first-principles calculations were effective to determining the origin of the phase transition and the H/D isotope effect in hydrogen-bonded dielectric materials.

Multicomponent DFT study of geometrical H/D isotope effect on hydrogen-bonded organic conductor, κ-H 3 (Cat EDT-ST) 2

2017 ◽  
Vol 674 ◽  
pp. 168-172 ◽  
Author(s):  
Kaichi Yamamoto ◽  
Yusuke Kanematsu ◽  
Umpei Nagashima ◽  
Akira Ueda ◽  
Hatsumi Mori ◽  
...  
Keyword(s):  
Isotope Effect ◽  
Dft Study ◽  
Organic Conductor ◽  
Hydrogen Bonded

Theoretical study of hydrogen bonding interactions in substituted nitroxide radicals

2021 ◽  
Author(s):  
Thufail M. Ismail ◽  
Neetha Mohan ◽  
P. K. Sajith
Keyword(s):  
Hydrogen Bonding ◽  
Interaction Energy ◽  
Electrostatic Potential ◽  
Molecular Electrostatic Potential ◽  
Theoretical Study ◽  
Nitroxide Radicals ◽  
Hydrogen Bonding Interactions ◽  
Bonded Complexes ◽  
Hydrogen Bonded

Interaction energy (Eint) of hydrogen bonded complexes of nitroxide radicals can be assessed in terms of the deepest minimum of molecular electrostatic potential (Vmin).

Theoretical study for photoinduced phase transition in superstructures

2003 ◽  
Vol 137 (1-3) ◽  
pp. 1223-1224
Author(s):  
Tohru Kawamoto ◽  
Shuji Abe
Keyword(s):  
Phase Transition ◽  
Theoretical Study
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