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A molecular dynamics study of ejection of molecules from a vibrationally excited “track” in an amorphous solid
Author(s) -
Cui S. T.,
Johnson R. E.
Publication year - 2009
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.560360859
Subject(s) - excited state , diatomic molecule , atomic physics , anharmonicity , excitation , molecular dynamics , molecule , molecular physics , center of mass (relativistic) , chemistry , physics , classical mechanics , energy–momentum relation , condensed matter physics , computational chemistry , organic chemistry , quantum mechanics
A molecular dynamics program is developed to study the ejection of molecules from a weakly bound, amorphous solid made up of diatomic molecules. The ejection is calculated in response to an amount of energy deposited, presumably by an incident fast particle, in vibrational excitation of the molecules within a cylindrical volume about the particle's “track”. The anharmonic distortion of the “excited” molecules in the “track” can lead to rapid energy transfer to the center of mass motion producing to sputtering. When the level of vibration excitation is small, nearly harmonic motion, virtually no energy transfer occurs in the time scales of interest. At the larger energy depositions considered, the number of molecules ejected vs. energy deposited per unit path length is consistent with recent simulations using structureless particles and with an analytic model for ejection due to a “pressure pulse”.