32 Z 〈 r $^{2}$〉1 / 2 Electronic 1-loop QED Scr.QED Recoil 2-loop QED Total Experiment Ref. structure theory 10 3.005(2) 15.9068(3) -0.0200 0.0058(2) -0.0042 0.0000 15.8883(4) 15.8887(2) [17] 15 3.189(2) 25.8848(3) -0.0833 0.0165(3) -0.0071 0.00005 25.8110(4) 25.814(3) [74] 18 3.427(2) 32.0061(3) -0.1569 0.0260(4) -0.0081 0.0001 31.8673(5) 31.8664(9) [17] 20 3.476(1) 36.1633(3) -0.2260 0.0338(5) -0.0100 0.0002 35.9612(6) 35.9625(25) [75] 21 3.544(2) 38.2679(3) -0.2673 0.0380(6) -0.0099 0.00024 38.0289(7) 38.02(4) [76] 26 3.737(2) 49.1030(3) -0.5565 0.0646(8) -0.0126 0.0007(1) 48.5991(9) 48.5982(8) [24] 48.5997(10) [77] 28 3.775(1) 53.6031(3) -0.7169 0.0775(9) -0.0142 0.0009(1) 52.9504(10) 52.9501(11) [78, 79] 30 3.929(1) 58.2135(3) -0.9070 0.0917(10) -0.0149 0.0013(2) 57.3846(10) 57.3839(30) [80] 36 4.188(1) 72.8021(6) -1.6859 0.1428(14) -0.0167 0.0029(5) 71.2451(15) 71.243(8) [81] 71.241(11) [82] 40 4.270(1) 83.2706(11) -2.4107 0.1840(17) -0.0195 0.0046(10) 81.0289(23) 47 4.544(4) 103.3426(17) -4.1673 0.2708(22) -0.0233 0.0094(21) 99.4321(35) 99.438(7) [83] 50 4.654(1) 112.7440(22) -5.1431 0.3141(26) -0.0238 0.0124(30) 107.9036(45) 107.911(7) [20] 52 4.743(3) 119.3127(24) -5.8777 0.3447(28) -0.0243 0.0147(35) 113.770(5) 54 4.787(5) 126.1471(31) -6.6851 0.3773(32) -0.0257 0.0175(40) 119.831(6) 119.820(8) [20] 60 4.912(2) 148.3812(40) -9.5873 0.4841(42) -0.0305 0.0271(15) 139.275(6) Table X. Individual contributions to the 2 p$_{1}$$_{/}$$_{2}$ − 2 s transition energy in Li-like ions, in eV.