In order to make a comparison between various methods and models
transparent, in the present calculations we only consider one
collective variable , an average axial quadrupole moment of the
mass distribution in the nucleus:
To account for pairing correlations, we applied the BCS approximation
to the density-dependent -pairing interaction (DDDI):
The calculations were performed using the code HFODD
(v2.19l)[10,11,12] that allows
for an arbitrary symmetry breaking. For the basis, we took the lowest
1140 single-particle states of the deformed harmonic oscillator. This
corresponds to 14 oscillator shells at the spherical point. Based on
the HFODD self-consistent wave-functions, the collective mass
tensor components and ZPE corrections were computed. In principle, all
the collective-tensor components with multipolarities
can be calculated.
In this study, only specific static fission paths are considered; they
have been obtained in the calculations presented in
Ref.[13]. Specifically, for the fermium isotopes
considered, one predicts both reflection-symmetric (s) and
reflection-asymmetric (a) fission valleys. There are two kinds of
symmetric paths predicted; namely, the valley that corresponds to
elongated fission fragments (E), and that with more compact (C)
fragments that resemble spherical Sn clusters when approaching
Fm. (The shorthand notation sEF, used in the following, means
symmetric, elongated-fragments fission path; similarly aEF and sCF.)