Abstract: Under applied electric field，the total energy，first ionization energy，electron affinity，electronegativity，

infrared spectroscopy，Raman spectroscopy and dissociation potential energy surface of tetrachloromethane are

studied by using B3LYP /6-311G( d，p) method and group optimization method. The effects of external electric field

on the molecular are discussed. The results show that the optimization effect of B3LYP /6-311G( d，p) base set without

electric field is consistent with the experimental results; the absolute values of total energy，first ionization

energy and electron affinity are independent of the direction of electric field，and the total energy and first ionization

energy decrease with the increase of electric field intensity，while the electron affinity increases with the increase of

electric field intensity. The electronegativity decreases with the increase of the positive electric field，and increases

first and then decreases with the increase of the negative electric field; the infrared absorption intensity decreases rapidly

at first and then increases with the increase of the electric field; the infrared strongest absorption peaks and Raman

peaks show a red shift with the positive electric field，and the infrared strongest absorption peaks show a blue

shift with the negative electric field. With the increase of external electric field，C1-Cl5 bond potential well value decreases

gradually，energy barrier decreases gradually，bond binding ability decreases gradually. When the external electric

field increases to -0.0015 a.u.，the C1-Cl5 bond barrier disappears and the molecule dissociates. External electric

field provides a new idea for the degradation of toxic organic pollutant tetrachloromethane and similar toxic substances.

Key words: external electric field, tetrachloromethane, electronegativity, spectral properties, dissociation