\begin{table}%t4 \caption{\label{tab:13CH3CN} Lower state quantum numbers of rotational transitions of $^{13}$CH$_3$CN from present work, frequencies (MHz), uncertainties unc. (kHz), and residuals o$-$c (kHz) between observed frequencies and those calculated from the final set of spectroscopic parameters.} \par %\centerline \small\begin{tabular}{crcrr | crcrr | crcrr} \hline \hline $J''$ & \multicolumn{1}{c}{$K''$} & Frequency & \multicolumn{1}{c}{unc.} & o$-$c & $J''$ & \multicolumn{1}{c}{$K''$} & Frequency & \multicolumn{1}{c}{unc.} & o$-$c & $J''$ & \multicolumn{1}{c}{$K''$} & Frequency & \multicolumn{1}{c}{unc.} & o$-$c \\ \cline{1-5} \cline{6-15} 18 & 6 & ~339137.3433 & 1.0 & $-$0.3 & 43 & 0 & 784895.847 & 50 & 43 & 56 & 3 & 1015544.407 & 20 & 21 \\ 18 & 3 & ~339309.0082 & 1.0 & 0.3 & 44 & 12 & 800553.654 & 150 & $-$143 & 56 & 2 & 1015636.946 & 30 & 17 \\ 18 & 2 & ~339340.8330 & 1.0 & 0.4 & 44 & 11 & 800891.319 & 100 & $-$105 & 56 & 1 & 1015692.486 & 30 & 17 \\ 18 & 1 & ~339359.9326 & 1.0 & $-$0.0 & 44 & 10 & 801200.157 & 50 & 13 & 56 & 0 & 1015711.009 & 50 & 24 \\ 18 & 0 & ~339366.2998 & 1.0 & $-$0.4 & 44 & 9 & 801479.794 & 50 & $-$44 & 57 & 12 & 1030736.928 & 150 & 51 \\ 24 & 12 & 445241.735 & 30 & $-$11 & 44 & 8 & 801730.374 & 50 & $-$18 & 57 & 10 & 1031558.219 & 50 & 63 \\ 24 & 11 & 445432.247 & 50 & 73 & 44 & 7 & 801951.637 & 50 & $-$72 & 57 & 8 & 1032231.921 & 30 & 22 \\ 24 & 10 & 445606.353 & 50 & 51 & 44 & 6 & 802143.651 & 50 & $-$47 & 57 & 7 & 1032513.150 & 20 & 46 \\ 24 & 9 & 445764.100 & 50 & 41 & 44 & 5 & 802306.261 & 50 & $-$22 & 57 & 6 & 1032757.054 & 20 & 10 \\ 24 & 8 & 445905.405 & 30 & 22 & 44 & 4 & 802439.367 & 50 & $-$30 & 57 & 5 & 1032963.632 & 20 & 11 \\ 24 & 7 & 446030.264 & 30 & 48 & 44 & 3 & 802542.979 & 50 & $-$7 & 57 & 4 & 1033132.760 & 20 & 7 \\ 24 & 6 & 446138.527 & 20 & 19 & 44 & 2 & 802616.938 & 50 & $-$71 & 57 & 2 & 1033358.435 & 20 & 14 \\ 24 & 5 & 446230.222 & 20 & 8 & 44 & 1 & 802661.445 & 50 & 10 & 57 & 1 & 1033414.879 & 20 & 12 \\ 24 & 4 & 446305.355 & 50 & 56 & 44 & 0 & 802676.201 & 50 & $-$44 & 57 & 0 & 1033433.720 & 20 & 35 \\ 24 & 3 & 446363.747 & 20 & 17 & 45 & 9 & 819230.822 & 100 & $-$149 & 60 & 12 & 1083745.465 & 50 & $-$34 \\ 24 & 2 & 446405.494 & 20 & 11 & 45 & 8 & 819486.798 & 100 & $-$45 & 60 & 11 & 1084195.000 & 50 & $-$0 \\ 24 & 1 & 446430.566 & 20 & 24 & 45 & 7 & 819712.787 & 50 & $-$70 & 60 & 9 & 1084978.318 & 50 & $-$54 \\ 24 & 0 & 446438.899 & 20 & 3 & 45 & 6 & 819908.940 & 50 & 20 & 60 & 8 & 1085311.933 & 50 & $-$4 \\ 25 & 12 & 463032.948 & 50 & 70 & 45 & 5 & 820075.010 & 50 & 54 & 60 & 6 & 1085862.162 & 50 & $-$1 \\ 25 & 11 & 463230.857 & 50 & 42 & 45 & 4 & 820210.775 & 50 & $-$120 & 60 & 4 & 1086255.771 & 50 & $-$44 \\ 25 & 10 & 463411.809 & 80 & 2 & 45 & 3 & 820316.536 & 50 & $-$147 & 60 & 3 & 1086393.678 & 50 & $-$40 \\ 25 & 9 & 463575.821 & 50 & 38 & 45 & 2 & 820392.237 & 50 & $-$39 & 60 & 2 & 1086492.216 & 50 & $-$45 \\ 25 & 6 & 463965.038 & 50 & 45 & 45 & 1 & 820437.489 & 50 & $-$156 & 61 & 13 & 1100909.779 & 100 & 92 \\ 25 & 5 & 464060.345 & 50 & 31 & 45 & 0 & 820452.748 & 50 & $-$22 & 61 & 12 & 1101404.872 & 50 & 11 \\ 25 & 4 & 464138.400 & 50 & 41 & 46 & 9 & 836978.116 & 50 & $-$59 & 61 & 10 & 1102278.334 & 80 & $-$15 \\ 25 & 3 & 464199.111 & 50 & 18 & 46 & 8 & 837239.242 & 80 & $-$108 & 61 & 9 & 1102656.306 & 30 & $-$19 \\ 25 & 2 & 464242.534 & 50 & 42 & 46 & 7 & 837469.939 & 50 & $-$107 & 61 & 7 & 1103293.992 & 20 & $-$5 \\ 25 & 1 & 464268.543 & 50 & 3 & 46 & 6 & 837670.126 & 50 & $-$46 & 61 & 6 & 1103553.424 & 20 & $-$17 \\ 25 & 0 & 464277.228 & 50 & 5 & 46 & 5 & 837839.510 & 50 & $-$137 & 61 & 5 & 1103773.128 & 50 & $-$18 \\ 26 & 13 & 480598.910 & 200 & 15 & 46 & 4 & 837978.301 & 50 & $-$102 & 61 & 4 & 1103953.032 & 20 & 5 \\ 26 & 12 & 480821.850 & 100 & 20 & 46 & 3 & 838086.283 & 50 & $-$99 & 61 & 3 & 1104093.012 & 20 & 4 \\ 26 & 10 & 481215.078 & 50 & $-$26 & 46 & 2 & 838163.526 & 50 & $-$15 & 61 & 2 & 1104193.040 & 20 & 4 \\ 26 & 9 & 481385.284 & 50 & $-$5 & 46 & 1 & 838209.741 & 50 & $-$109 & 61 & 1 & 1104253.061 & 20 & $-$8 \\ 26 & 8 & 481537.813 & 50 & 67 & 46 & 0 & 838225.208 & 50 & $-$81 & 61 & 0 & 1104273.082 & 20 & $-$0 \\ 26 & 7 & 481672.435 & 50 & 22 & 49 & 12 & 889171.685 & 80 & 46 & 62 & 13 & 1118556.496 & 100 & 4 \\ 26 & 6 & 481789.313 & 50 & 78 & 49 & 11 & 889544.894 & 100 & 15 & 62 & 12 & 1119059.047 & 50 & 54 \\ 26 & 5 & 481888.243 & 100 & 77 & 49 & 10 & 889886.195 & 80 & 32 & 62 & 11 & 1119522.099 & 80 & 76 \\ 26 & 4 & 481969.220 & 50 & 55 & 49 & 9 & 890195.361 & 80 & 5 & 62 & 10 & 1119945.421 & 40 & 16 \\ 26 & 3 & 482032.241 & 50 & 42 & 49 & 8 & 890472.317 & 50 & $-$20 & 62 & 8 & 1120672.581 & 20 & 6 \\ 26 & 2 & 482077.319 & 50 & 78 & 49 & 7 & 890716.982 & 50 & $-$12 & 62 & 7 & 1120976.075 & 20 & $-$1 \\ 26 & 1 & 482104.227 & 50 & $-$48 & 49 & 6 & 890929.260 & 50 & 28 & 62 & 6 & 1121239.357 & 50 & $-$1 \\ 26 & 0 & 482113.311 & 50 & 24 & 49 & 5 & 891108.967 & 50 & 4 & 62 & 5 & 1121462.318 & 20 & 5 \\ 27 & 12 & 498608.539 & 150 & 24 & 49 & 4 & 891256.131 & 50 & 16 & 62 & 3 & 1121786.918 & 20 & 12 \\ 27 & 11 & 498821.247 & 150 & $-$178 & 49 & 3 & 891370.650 & 50 & 21 & 62 & 2 & 1121888.415 & 20 & 1 \\ 27 & 10 & 499016.263 & 100 & 151 & 49 & 2 & 891452.462 & 50 & 5 & 62 & 1 & 1121949.341 & 20 & 7 \\ 27 & 8 & 499350.520 & 50 & 18 & 49 & 1 & 891501.579 & 50 & 12 & 62 & 0 & 1121969.656 & 30 & 12 \\ 27 & 7 & 499490.120 & 50 & 47 & 49 & 0 & 891517.973 & 50 & 33 & 63 & 15 & 1135059.113 & 150 & 40 \\ 27 & 6 & 499611.153 & 50 & 4 & 50 & 13 & 906470.254 & 150 & 42 & 63 & 11 & 1137177.559 & 50 & $-$3 \\ 27 & 5 & 499713.686 & 50 & 4 & 50 & 12 & 906882.928 & 50 & 9 & 63 & 10 & 1137607.095 & 30 & 4 \\ 27 & 4 & 499797.648 & 50 & 17 & 50 & 11 & 907263.229 & 80 & 15 & 63 & 9 & 1137996.224 & 20 & $-$3 \\ 27 & 2 & 499909.654 & 50 & 11 & 50 & 10 & 907610.895 & 100 & $-$53 & 63 & 8 & 1138344.827 & 50 & 9 \\ 27 & 1 & 499937.687 & 50 & 27 & 50 & 9 & 907925.987 & 50 & 1 & 63 & 7 & 1138652.740 & 20 & 15 \\ 27 & 0 & 499947.025 & 50 & 24 & 50 & 8 & 908208.205 & 50 & 3 & 63 & 6 & 1138919.837 & 20 & 8 \\ 28 & 11 & 516613.238 & 80 & 10 & 50 & 7 & 908457.487 & 80 & 4 & 63 & 5 & 1139146.023 & 20 & 2 \\ 28 & 10 & 516814.764 & 80 & 23 & 50 & 6 & 908673.729 & 50 & $-$2 & 63 & 4 & 1139331.185 & 50 & $-$27 \\ 28 & 9 & 516997.294 & 50 & $-$16 & 50 & 5 & 908856.837 & 50 & $-$22 & 63 & 3 & 1139475.324 & 20 & $-$2 \\ 28 & 3 & 517691.313 & 50 & 22 & 50 & 4 & 909006.769 & 50 & $-$23 & 63 & 2 & 1139578.300 & 20 & $-$7\\ \hline 28 & 2 & 517739.642 & 50 & 31 & 50 & 3 & 909123.446 & 50 & $-$23 & 63 & 1 & 1139640.092 & 20 & $-$19 \\ 28 & 1 & 517768.629 & 50 & 19 & 50 & 2 & 909206.838 & 50 & $-$7 & 64 & 14 & 1153276.801 & 200 & 131 \\ 28 & 0 & 517778.310 & 50 & 31 & 50 & 1 & 909256.926 & 50 & 43 & 64 & 12 & 1154351.199 & 30 & $-$21 \\ 34 & 16 & 621760.772 & 50 & 10 & 50 & 0 & 909273.539 & 50 & $-$26 & 64 & 9 & 1155657.985 & 20 & $-$18 \\ 34 & 14 & 622447.422 & 30 & $-$26 & 51 & 12 & 924589.926 & 80 & 22 & 64 & 8 & 1156011.566 & 20 & 4 \\ 34 & 11 & 623309.671 & 20 & 14 & 51 & 11 & 924977.218 & 100 & $-$13 & 64 & 7 & 1156323.830 & 20 & $-$27 \\ 34 & 10 & 623551.857 & 20 & 5 & 51 & 9 & 925652.265 & 50 & 8 & 64 & 6 & 1156594.758 & 20 & $-$9 \\ 34 & 9 & 623771.262 & 20 & $-$14 & 51 & 8 & 925939.684 & 50 & $-$7 & 64 & 4 & 1157012.016 & 20 & 5 \\ 34 & 7 & 624141.443 & 20 & $-$28 & 51 & 7 & 926193.576 & 80 & $-$5 & 64 & 3 & 1157158.166 & 20 & $-$13 \\ 34 & 6 & 624292.087 & 20 & $-$5 & 51 & 5 & 926600.341 & 80 & 2 & 64 & 2 & 1157262.634 & 20 & 8 \\ 34 & 4 & 624524.053 & 20 & $-$26 & 51 & 4 & 926753.052 & 80 & 8 & 64 & 0 & 1157346.208 & 20 & $-$2 \\ 34 & 2 & 624663.446 & 20 & 24 & 51 & 3 & 926871.878 & 50 & $-$0 & 65 & 13 & 1171464.851 & 100 & 10 \\ 34 & 1 & 624698.263 & 20 & $-$13 & 51 & 2 & 926956.781 & 50 & $-$14 & 65 & 11 & 1172472.160 & 80 & $-$102 \\ 34 & 0 & 624709.879 & 20 & $-$16 & 51 & 1 & 927007.756 & 50 & $-$2 & 65 & 9 & 1173314.209 & 30 & $-$5 \\ 35 & 16 & 639490.666 & 100 & 54 & 51 & 0 & 927024.756 & 50 & 8 & 65 & 8 & 1173672.712 & 20 & $-$8 \\ 35 & 14 & 640196.404 & 60 & 27 & 55 & 12 & 995373.248 & 100 & 44 & 65 & 6 & 1174264.072 & 20 & $-$12 \\ 35 & 12 & 640810.267 & 30 & $-$44 & 55 & 10 & 996168.138 & 100 & 60 & 65 & 4 & 1174687.142 & 50 & $-$23 \\ 35 & 11 & 641082.493 & 50 & $-$47 & 55 & 9 & 996511.966 & 50 & $-$72 & 65 & 3 & 1174835.374 & 20 & $-$3 \\ 35 & 9 & 641556.961 & 50 & $-$22 & 55 & 7 & 997092.349 & 20 & 21 & 65 & 2 & 1174941.285 & 20 & $-$1 \\ 35 & 7 & 641937.464 & 20 & 1 & 55 & 5 & 997528.396 & 20 & 33 & 65 & 1 & 1175004.858 & 20 & 9 \\ 35 & 6 & 642092.248 & 50 & $-$20 & 55 & 4 & 997692.055 & 20 & $-$4 & 65 & 0 & 1175026.016 & 30 & $-$23 \\ 35 & 5 & 642223.312 & 50 & $-$53 & 55 & 3 & 997819.444 & 30 & $-$3 & 66 & 12 & 1189621.606 & 120 & 111 \\ 35 & 4 & 642330.670 & 30 & $-$28 & 55 & 2 & 997910.473 & 20 & $-$2 & 66 & 11 & 1190111.236 & 150 & $-$17 \\ 35 & 3 & 642414.174 & 50 & $-$52 & 55 & 1 & 997965.147 & 30 & 40 & 66 & 10 & 1190558.963 & 120 & $-$107 \\ 35 & 2 & 642473.884 & 30 & $-$29 & 55 & 0 & 997983.325 & 20 & 6 & 66 & 9 & 1190964.780 & 20 & 6 \\ 35 & 0 & 642521.653 & 30 & $-$24 & 56 & 12 & 1013057.279 & 100 & $-$164 & 66 & 6 & 1191927.684 & 25 & $-$10 \\ 43 & 8 & 783970.101 & 80 & 18 & 56 & 9 & 1014215.234 & 20 & 7 & 66 & 5 & 1192163.522 & 20 & 8 \\ 43 & 6 & 784374.602 & 50 & 11 & 56 & 8 & 1014528.429 & 50 & $-$48 & 66 & 4 & 1192356.610 & 20 & 23 \\ 43 & 5 & 784533.705 & 50 & $-$10 & 56 & 7 & 1014805.211 & 20 & 40 & 66 & 3 & 1192506.829 & 20 & $-$6 \\ 43 & 3 & 784765.344 & 50 & $-$36 & 56 & 6 & 1015045.237 & 30 & 40 & 66 & 2 & 1192614.182 & 20 & $-$17 \\ 43 & 2 & 784837.839 & 50 & 11 & 56 & 5 & 1015248.484 & 20 & 23 & 66 & 1 & 1192678.616 & 20 & $-$19 \\ 43 & 1 & 784881.204 & 50 & $-$104 & 56 & 4 & 1015414.879 & 20 & $-$1 & 66 & 0 & 1192700.114 & 20 & $-$2 \\ \hline \end{tabular} \end{table}