compare adsoption  of H2O on TiO2[110] using a simple model structure:
the model surface consists of 2 layers TiO2, (1x1)
-- the bottom layer of the slab will be kept frozen
-- 3 setups will be tested
1. standard relaxation, minimizing the Hellmann-Feyman forces
2. constrained MD, fixing the bond lengths and angle of H2O,
   the system is coupled to an ANDERSEN thermostat
   2.1. in a microcanonical NVE ensemble (no collisions with
        the thermostat
   2.2. in a canonical ensembe at T= 10K (to be close to the 
        standard relaxation (0K)
   to keep the computing time reasonable, the number of steps
   in the MD is limited to 100, (100 fs) which implies that 
   the MD is NOT CONVERGED.


