Open AccessElectron-vibration approximation method for hydrogen isotope compounds TiH2,TiD2 and TiT2
Author(s) -
Zhang Li,
Zhu Zheng-He,
Yang Benfu,
Xinggui Long,
Siyi Luo
Publication year - 2006
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.55.5418
Subject(s) - atomic physics , molecule , density functional theory , materials science , hydrogen , vibration , electron , thermodynamics , entropy (arrow of time) , basis set , titanium , isotope , physics , quantum mechanics , metallurgy
The ground states of TiH2,TiD2 and TiT2 are determined as 3A2 based on atomic and molecular statics and ground theory. The energy E, heat capacity Cv and entropy S of hydrogen isotopic molecules and its titanium compounds have been calculated using density functional theory (DFT) with basis set 6-311G**. The electronic and vibrational energy and entropy of single molecules TiH2,TiD2 and TiT2 are used as the energy and entropy in their solid states approximately, which is called the electron-vibration motion approximation theory(EVMAT). The calculated results of hydrogenation (and of its isotopes) thermodymical functions ΔH0, ΔS0, ΔG0 and equilibrium pressure of metallic titanium changing with temperature are in good agreement with experimental data, which confirms EVMAT theory further.