Solvation pressure in ethanol by molecular dynamics simulations

The results of all-atom molecular dynamics simulations of ethanol liquid and vapor using a modified version of the Cornell field W. D. Cornell and P. Cieplak, J. Am. Chem. Soc. 117, 5179 1995 are presented. Excellent agreement with experiment is obtained for density, compressibility, and cohesive energy density. The ethanol liquid is subjected to uniform hydrostatic pressure in the range 1 to 15 kbar at room temperature and the vibrational frequency spectra are calculated. The peak frequencies of seven major vibrational modes are found to be accurate to within 100 cm 1 of their experimental positions and the change of frequency as a function of pressure is consistent with Raman data. The change in bond length is found to be consistent with the solvation pressure model for all bonds except for O-H due to hydrogen bonding.