Lastly, the phase-space factor G 0 ν ν must also be calculated. It depends on the total released kinetic energy ( Q = M nucleus before − − M nucleus after − − 2 m electron , i.e. " Q -value") and the atomic number Z . Methods use Dirac wave functions, finite nuclear sizes and electron screening. There exist high-precision results for G 0 ν ν for various nuclei, ranging from about 0.23 (for 52 128 T e → → 54 128 X e ), and 0.90 ( 32 76 G e → → 34 76 S e ) to about 24.14 ( 60 150 N d → → 62 150 S m ).