  Parametric correlations of energy spectra of quantum chaotic systems are
presented in the orthogonal-unitary and symplectic-unitary crossover region.
The spectra are allowed to disperse as a function of two external
perturbations: one of which preserves time-reversal symmetry, while the other
violates it. Exact analytical expressions for the parametric two-point
autocorrelation function of the density of states are derived in the crossover
region by means of the supermatrix method. For the orthogonal-unitary
crossover, the velocity distributions is determined and shown to deviate from
Gaussian.
