Number of states within an energy interval divided by volume and that energy interval. Symbol: NE.
Number of states within an energy interval divided by that energy interval. Symbol: rE.
Sources: Green Book, 2nd ed., p. 37 (https://goldbook.iupac.org/files/pdf/green_book_2ed.pdf) PAC, 1996, 68, 149. 'A glossary of terms used in chemical kinetics, including reaction dynamics (IUPAC Recommendations 1996)' on page 162 (https://doi.org/10.1351/pac199668010149) Green Book, 2nd ed., p. 39 (https://goldbook.iupac.org/files/pdf/green_book_2ed.pdf)