Update atomic.h #6970

Job	Run time
classicmode_1d_3dgrid	4m 35s
classicmode_3d	7m 59s
kilonova_1d_1dgrid	4m 47s
kilonova_1d_3dgrid	5m 14s
kilonova_2d_2dgrid	7m 27s
kilonova_2d_2dgrid_barnesthermalisation	5m 19s
kilonova_2d_2dgrid_expansionopac	5m 25s
kilonova_2d_2dgrid_xcomgammaphotoion	5m 31s
kilonova_2d_3dgrid	7m 19s
nebular_1d_3dgrid	12m 6s
nebular_1d_3dgrid_limitbfest	14m 9s
classicmode_1d_3dgrid testmode ON	16m 26s
classicmode_3d testmode ON	16m 27s
kilonova_1d_1dgrid testmode ON	12m 0s
kilonova_1d_3dgrid testmode ON	13m 3s
kilonova_2d_2dgrid testmode ON	16m 9s
kilonova_2d_2dgrid_barnesthermalisation testmode ON	16m 10s
kilonova_2d_2dgrid_expansionopac testmode ON	15m 6s
kilonova_2d_2dgrid_xcomgammaphotoion testmode ON	15m 19s
kilonova_2d_3dgrid testmode ON	15m 19s
nebular_1d_3dgrid testmode ON	15m 19s
nebular_1d_3dgrid_limitbfest testmode ON	15m 16s
combine_checksums	19s
	4h 6m 44s

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