  We present the implementation of a quadratically convergent Self-consistent
field (QCSCF) algorithm based on an adaptive trust-radius optimization scheme
for restricted open-shell Hartree-Fock (ROHF), restricted Hartree-Fock (RHF),
and unrestricted Hartree-Fock (UHF) references. The algorithm can exploit
Cholesky decomposition (CD) of the two-electron integrals to allow calculations
on larger systems. The most important feature of the QCSCF code lies in its
black-box nature -- probably the most important quality desired by a generic
user. As shown for pilot applications, it does not require one to tune the
self-consistent field (SCF) parameters (damping, Pulay's DIIS, and other
similar techniques) in difficult-to-converge molecules. Also, it can be used to
obtain a very thigh convergence with extended basis set - a situation often
needed when computing high-order molecular properties - where the standard SCF
algorithm starts to oscillate. Nevertheless, trouble may appear even with a
QCSCF solver. In this respect, we discuss what can go wrong, focusing on the
multiple UHF solutions of ortho-benzyne
