Dear Merlin, the pseudopotential Ni.pbe-sp-mt_gipaw.UPF includes 3s and 3p semicore states as Paolo giannozzi suggested and it is a norm conseving pseudopotential. As far as I remember it was also tested on bulk Ni and the agreement with the experimental pressure was fine. Of course, being a Norm conseving with semicore states, it will require a cutoff of at least of 150 Ryd and not of 27.0 Ryd as your input file seems to suggest.
M. &system >> ibrav=2, celldm(1) =6.65, nat= 1, ntyp= 1, >> nspin=2, >> starting_magnetization(1)=0.5, >> degauss=0.02, >> smearing='mp', >> occupations='smearing', >> ecutwfc =27.0 >> ecutrho =300.0 >> / -- * * * * Matteo Calandra, Charge de Recherche (CR1) Institut de Min?ralogie et de Physique des Milieux Condens?s de Paris Universit? Pierre et Marie Curie, tour 16, case 115 4 Place Jussieu, 75252 Paris Cedex 05 France Tel: +33-1-44 27 52 16 Fax: +33-1-44 27 37 85 http://www.impmc.jussieu.fr/~calandra