Nabi, Jameel-UnCakmak, NeclaIftikhar, Zafar2024-09-292024-09-2920161434-60011434-601Xhttps://doi.org/10.1140/epja/i2016-16005-6https://hdl.handle.net/20.500.14619/6320First-forbidden (FF) transitions can play an important role in decreasing the calculated half-lives specially in environments where allowed Gamow-Teller (GT) transitions are unfavored. Of special mention is the case of neutron-rich nuclei where, due to phase-space amplification, FF transitions are much favored. We calculate the allowed GT transitions in various pn-QRPA models for even-even neutron-rich isotopes of nickel. Here we also study the effect of deformation on the calculated GT strengths. The FF transitions for even-even neutron-rich isotopes of nickel are calculated assuming the nuclei to be spherical. Later we take into account deformation of nuclei and calculate GT + unique FF transitions, stellar beta-decay rates, energy rate of beta-delayed neutrons and probability of beta-delayed neutron emissions. The calculated half-lives are in excellent agreement with measured ones and might contribute in speeding-up of the r-matter flow.eninfo:eu-repo/semantics/closedAccessWeak Interaction RatesMicroscopic CalculationsHalf-LivesR-ProcessNucleiShellPredictionsRpaArticle10.1140/epja/i2016-16005-62-s2.0-849554752641Q252WOS:000375215400001Q2