Open AccessFirst principles calculations of solid phase transition of nitromethane
Author(s) -
Zhang Li,
Lang Chen
Publication year - 2014
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.63.098105
Subject(s) - intramolecular force , materials science , dihedral angle , nitromethane , intermolecular force , phase transition , density functional theory , hydrogen bond , lattice (music) , chemical physics , condensed matter physics , thermodynamics , chemistry , computational chemistry , molecule , physics , organic chemistry , acoustics , stereochemistry
The solid phase transition in crystals prepared from molecular energetic materials under extreme conditions is important for understanding the detonation mechanisms. By applying the first principles density functional calculations, a detailed theoretical study of the lattice parameters and molecular structures, equations of state, densities of state for solid nitromethane is reported. By analyzing the pressure dependence of lattice parameters, a sudden change of the lattice parameters occurs between 10-12 GPa, implying that a transition has taken place. It is also found that the maximum dihedral angle of H-C-N-O has increased from 155.3° to 177.5°, indicating that a rotation of the methyl group from a staggered to an eclipsed conformation occurs in the pressure range 11–12 GPa. Before the phase transition, the intramolecular O … H–C interactions are mainly of hydrogen bonds. After the phase transition, the intramolecular and intermolecular O … H interactions are mainly of the hydrogen bonds. Phase transition also affects the reduced ratio of band gap and the density of state near the Fermi level.