  Densified silica can be obtained by different pressure and temperature paths
and for different stress conditions, hydrostatic or including shear. The
density is usually the macroscopic parameter used to characterize the different
compressed silica samples. The aim of our present study is to compare
structural modifications for silica glass, densified from several routes. For
this, densified silica glasses are prepared from cold and high temperature (up
to 1020 $^\circ$C) compressions. The different densified glasses obtained in
our study are characterized by micro-Raman spectroscopy. Intertetrahedral
angles from the main band relative to the bending mode decreases and their
values are larger for densified samples from high temperature compression than
those samples from cold compression. The relative amount of 3-membered rings
deduced from the D2 line area increases as a function of density for cold
compression. The temperature increase during the compression process induces a
decrease of the 3 fold ring population. Moreover, 3 fold rings are more
deformed and stressed for densified samples at room temperature at the expense
of those densified at high temperature. Temperature plays a main role in the
reorganization structure during the densification and leads to obtaining a more
relaxed structure with lower stresses than glasses densified from cold
compression. The role of hydrostatic or non-hydrostatic applied stresses on the
glass structure is discussed. From the Sen and Thorpe central force model,
intertetrahedral angle average value and their distribution are estimated.
