The influence of an electric field of silicalite-1-zeolite on the FTIR vibrational absorption spectrum of ethylene has been simulated and compared to experimental spectra. The presence of silicalite-1 produces a global shift and a change of the structure of vibrational bands. To explain the global shift of the nu(12) band (CH2 scissor mode) and therefore to estimate an effective average field produced by silicalite-1, Stark calculations were performed. These calculations were based on a tensorial formalism implemented in the D2hTDS-ST package [M. Sanzharov, M. Rotger, C. Wenger, M. Loete, V. Boudon, and A. Rouzee, J. Quant. Spectrosc. Radiat. Transf. 112, 41 (2011)]. The value of the field obtained using tensorial formalism (8-11 GV/m) is compared with values obtained using ab initio calculations. A theory of the molecular alignment in the electric field using tensorial formalism is also developed to model the interaction of ethylene in contact with a zeolite environment.