Description and analysis of the first spectrum of chromium, Cr I

velengths and estimated intens ities are presented for about 4400 lines of Cr I recorded photographically bet ween 11610 A in t he infra red and 1880 A 'in t he ultra vio let. Zeeman patterns, measured in magnetic fi elds of 3~000 and 85000 oersteds for a pproximately 10 pel'ce nt .of the I1I1es! are prese nted a lso. AnalysIs of t. he spectrum with t hese observational data has YIelded claSSIfi catIOns for about 80 perce nt of t he Cr I li nes as co mbina tions amonD" the ter ms that arise from the vario us confi g urat ions ass umed by th~ valence electrons of th~ atom in its excited and unexcited states . Of these ter ms 53 have been fo und due to the eve n ele~tron configura tions 3d5 ns, 3d' ns', 3d&, and 3d5 nd; and 115 due to the odd configurat io ns 3d' np and 3d' 4s np. Among both even and odd terms several series of t wo or more members have been found converg ing to t he ground state a 68 and to the metastable state a 6D of Cr II.