These authors remarked that the in the stationary laminar shear case
the Hoover-(qp) algorithm does not produce the correct flow pattern.
As evident from equ. 8.33 the shear force acts on the
``wrong'' component of the momentum - instead of .
This does not destroy the relation between and ,
but it results in an unphysical flow geometry.
Evans and Morris suggested a simple solution. Instead of 8.26
-8.27 they wrote
For simple Couette flow we now have
we have added optional Gaussian constraint
forces to keep . It is clear that equ. 8.39
has now the right form to produce Couette flow. In addition, these authors
demonstrated that their method produces the correct viscosity up to
much higher (non-linear regime) shear values than the Doll's tensor
Evans' and Morriss' equations of motion cannot be derived from a
perturbed Hamiltonian. However, they fulfill the necessary linear
response condition 8.12.
The above equations of motion are known as S'LLOD equations,
as they make use of the tensor
, the transpose of
the DOLL'S tensor
F. J. Vesely / University of Vienna