Abstract:The evaluated spectroscopic data are presented for known nuclides of mass 64 (Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge). Excited-state data are nonexistent for 64Mn and 64Fe. Radioactive decay data for 64Mn are not available and those for 64Fe, 64Co and 64Ge are not considered definitive. The following nuclides have not yet been identified but, amongst other nuclides, have been included in theoretical calculations: 64Ca (92Ma60,91To03,91Hi10); 64Cr (95Re20,95Ri05,95Au04); 64As (95Au04); 64Se (93Sh11). The literature available up to June 25, 1996 has been consulted. This work supersedes earlier evaluations of A=64 published in Nuclear Data Sheets (91Si03,79Ha35,74Au04,67Ve09). Cutoff Date:Literature available up to June 25, 1996 has been consulted. General Policies and Organization of Material:See the January issue of Nuclear Data Sheets. Acknowledgments:The evaluator thanks Alfredo Galindo-Uribarri at Chalk River for discussions and communicating results of his recent in-beam experiment on 64Zn, prior to publication. General Comments:The statistical analysis of γ-ray data and deduced level schemes is carried out through computer codes available at Isotopes Project, Berkeley and Nuclear Data Center, Brookhaven. The methodology and procedures for some of these codes are described by 86BrZQ and 86Br21. A general 3% uncertainty is assumed in quoted theoretical internal conversion coefficients taken mainly from 68Ha53. The values of μ and Q are from compilation by 89Ra17, when available.