  Anisotropic barostats are employed to carry out Molecular Dynamics
simulations where the volume is allowed to fluctuate with no constraints on the
shape of the simulation cell. Most of these algorithms are based on
second-order differential equations and share some common drawbacks, namely
they can lead to slowly damped oscillations in the equilibration phase, and
they do not allow to control efficiently the volume autocorrelation time. This
work develops the anisotropic version of stochastic cell rescaling, a
first-order stochastic barostat that overcomes these limits and can also be
employed in the production phase, resulting in the correct physical
fluctuations of the cell. The algorithm can be easily implemented in the
existing codes on top of the anisotropic Berendsen barostat. The validation
tests, performed on a number of crystal systems, show that the method is robust
against wide variations of the input parameter, which allows an efficient
control of the volume autocorrelation time.
