LMIXTAU
LMIXTAU = .TRUE. | .FALSE.
Default: LMIXTAU = .FALSE.
Description: send the kinetic energy density through the density mixer as well.
In many cases the density-mixing scheme works well enough without passing the kinetic-energy density through the mixer, which is why LMIXTAU=.FALSE., per default. However, when the selfconsistency cycle fails to converge for one of the algorithms exploiting density mixing, e.g, IALGO=38 or 48, one may set LMIXTAU=.TRUE. to have VASP pass the kinetic-energy density through the mixer as well. This sometimes helps to cure convergence problems in the selfconsistency cycle.