  A number of computer-generated models of water, methanol and ethanol are
considered at room temperature and ambient pressure, and also as a function of
temperature (for water and ethanol), and the potential model (for water only).
The Laplace matrices are determined, and various characteristics of this, such
as eigenvalues and eigenvectors, and the corresponding Laplace spectra are
calculated. It is revealed how the width of the spectral gap in the Laplace
matrix of H-bonded networks may be applied for characterising the stability of
the network. A novel method for detecting the presence percolated network in
these systems is also introduced.
