The rotational-vibrational correlations are important aspects of nuclear collective dynamics; they also contribute to nuclear binding through quantum zero-point corrections. To estimate the magnitude of the rotational-vibrational corrections, one usually applies RPA , GCM , or the Gaussian overlap approximation to GCM [71,72,73,74].
Regardless of the approach used, a key point is the choice of collective subspace. In the case of GCM and related methods, the collective manifold is determined by the set of external fields associated with the collective motion of the system. In most practical applications, one considers five quadrupole degrees of freedom that give rise to nuclear rotations and quadrupole vibrations, octupole deformations, and pairing vibrations [75,70]. An important step towards the microscopic description of correlation energies are the recent large-scale benchmark calculations of ground-state quadrupole correlations of binding energies for all even-even nuclei, from O up to the superheavy systems .