Wall clock time and date at job start Tue Mar 31 2020 06:55:07 AMSOL-version 7.1 by G. D. Hawkins, D. J. Giesen, G. C. Lynch, C. C. Chambers, I. Rossi, J. W. Storer, J. Li, J. D. Thompson, P. Winget, B. J. Lynch, D. Rinaldi, D. A. Liotard, C. J. Cramer, and D. G. Truhlar Copyright 2004 by Regents of the University of Minnesota. All rights reserved. Notice: recipients of this code are asked to comply with the user agreement in Section 1 of the documentation file. ******************************************************************************* * 1SCF - SCF CALCULATION WITHOUT GEOMETRY OPTIMIZATION * - USE EF ROUTINE FOR MINIMUM SEARCH (DEFAULT) * GEO-OK - OVERRIDE INTERATOMIC DISTANCE CHECK * TLIMIT= - A TIME OF 15. SECONDS REQUESTED * CHARGE - CHARGE ON SYSTEM= -1 * AM1 - THE AM1 HAMILTONIAN TO BE USED * SM5.42R - SM5.42R CALCULATIONS WILL BE PERFORMED * - CHARGE MODEL 2 WILL BE USED (CM2A) * - THE SOLVENT IS WATER ******************************************************************************* Atom NO. Chemical Bond length Bond angle Dihedral angle number (k) symbol (angstroms) (degrees) (degrees) (I) NA:I NB:NA:I NC:NB:NA:I NA NB NC 1 1 C 2 2 C 1.52997 * 1 3 3 H 1.09006 * 109.50554 * 2 1 4 4 C 1.53124 * 109.50316 * 239.88664 * 2 1 3 5 5 C 1.53125 * 109.16024 * 182.40294 * 4 2 1 6 6 H 1.08998 * 109.53179 * 177.61336 * 5 4 2 7 7 C 1.52992 * 109.50380 * 297.71206 * 5 4 2 8 8 C 1.53033 * 109.27628 * 57.65529 * 5 4 2 9 9 N 1.46855 * 109.52390 * 300.81659 * 8 5 4 10 10 C 1.46894 * 110.99811 * 185.84297 * 9 8 5 11 11 C 1.50698 * 109.47714 * 45.79289 * 10 9 8 12 12 C 1.38234 * 119.99864 * 269.72691 * 11 10 9 13 13 C 1.38240 * 120.00042 * 179.73771 * 12 11 10 14 14 C 1.38237 * 119.99625 * 0.53343 * 13 12 11 15 15 C 1.50699 * 120.00006 * 179.76815 * 14 13 12 16 16 N 1.46507 * 109.47017 * 269.97810 * 15 14 13 17 17 C 1.34776 * 119.99920 * 179.97438 * 16 15 14 18 18 O 1.21274 * 120.00010 * 359.97438 * 17 16 15 19 19 C 1.50700 * 119.99637 * 179.97438 * 17 16 15 20 20 S 1.81004 * 109.46979 * 179.97438 * 19 17 16 21 21 C 1.76195 * 99.99915 * 179.97438 * 20 19 17 22 22 H 1.08004 * 120.00208 * 0.02562 * 21 20 19 23 23 C 1.38802 * 120.00045 * 179.97438 * 21 20 19 24 24 N 1.31632 * 119.99740 * 0.02562 * 23 21 20 25 25 Si 1.86797 * 120.00129 * 180.02562 * 23 21 20 26 26 H 1.48501 * 109.47246 * 89.99976 * 25 23 21 27 27 H 1.48507 * 109.47002 * 210.00124 * 25 23 21 28 28 H 1.48496 * 109.47088 * 329.99878 * 25 23 21 29 29 C 1.38241 * 119.99955 * 359.74017 * 14 13 12 30 30 C 1.38226 * 119.99931 * 359.97438 * 29 14 13 31 31 C 1.46850 * 111.19253 * 61.74635 * 9 8 5 32 32 H 1.09002 * 109.47153 * 299.91697 * 1 2 3 33 33 H 1.09001 * 109.46832 * 179.91888 * 1 2 3 34 34 H 1.09004 * 109.47261 * 59.91869 * 1 2 3 35 35 H 1.08996 * 109.52192 * 302.30778 * 4 2 1 36 36 H 1.09001 * 109.52366 * 62.50115 * 4 2 1 37 37 H 1.08997 * 109.47188 * 179.80297 * 7 5 4 38 38 H 1.09002 * 109.47455 * 299.80334 * 7 5 4 39 39 H 1.09001 * 109.47577 * 59.80252 * 7 5 4 40 40 H 1.09002 * 109.45949 * 180.80397 * 8 5 4 41 41 H 1.08999 * 109.45907 * 60.83085 * 8 5 4 42 42 H 1.09008 * 109.47122 * 165.79407 * 10 9 8 43 43 H 1.09004 * 109.47312 * 285.78939 * 10 9 8 44 44 H 1.08003 * 120.00115 * 359.97438 * 12 11 10 45 45 H 1.07994 * 120.00443 * 180.29334 * 13 12 11 46 46 H 1.09003 * 109.47176 * 29.97315 * 15 14 13 47 47 H 1.08992 * 109.47305 * 149.97641 * 15 14 13 48 48 H 0.97003 * 119.99841 * 359.97438 * 16 15 14 49 49 H 1.09003 * 109.47062 * 299.99865 * 19 17 16 50 50 H 1.09002 * 109.47229 * 60.00001 * 19 17 16 51 51 H 0.97001 * 119.99568 * 179.97438 * 24 23 21 52 52 H 1.07998 * 119.99557 * 180.02562 * 29 14 13 53 53 H 1.08003 * 120.00001 * 179.97438 * 30 29 14 54 54 H 1.09000 * 109.45313 * 178.24324 * 31 9 8 55 55 H 1.09000 * 109.46325 * 58.27473 * 31 9 8 Note: An asterisk (*) indicates this parameter was or will be optimized. Cartesian coordinates (angstroms) NO. Atom X Y Z 1 6 0.0000 0.0000 0.0000 2 6 1.5300 0.0000 0.0000 3 1 1.8939 1.0275 0.0000 4 6 2.0412 -0.7242 -1.2486 5 6 3.5712 -0.7722 -1.2106 6 1 3.9401 -1.3236 -2.0754 7 6 4.1279 0.6526 -1.2378 8 6 4.0229 -1.4729 0.0727 9 7 3.5093 -0.7417 1.2381 10 6 4.0373 -1.3051 2.4877 11 6 5.5199 -1.5362 2.3477 12 6 5.9890 -2.7494 1.8797 13 6 7.3488 -2.9596 1.7461 14 6 8.2397 -1.9604 2.0909 15 6 9.7223 -2.1913 1.9503 16 7 10.2494 -2.7531 3.1964 17 6 11.5612 -3.0434 3.3029 18 8 12.3052 -2.8401 2.3670 19 6 12.1035 -3.6207 4.5850 20 16 13.8839 -3.8996 4.4155 21 6 14.2438 -4.5565 6.0103 22 1 13.4535 -4.6733 6.7372 23 6 15.5427 -4.9248 6.3322 24 7 16.5058 -4.7829 5.4462 25 14 15.9242 -5.6219 8.0228 26 1 15.7770 -7.0993 7.9938 27 1 17.3168 -5.2705 8.4004 28 1 14.9822 -5.0500 9.0181 29 6 7.7707 -0.7493 2.5643 30 6 6.4108 -0.5371 2.6923 31 6 2.0409 -0.7231 1.2482 32 1 -0.3633 0.5125 0.8907 33 1 -0.3633 -1.0277 -0.0015 34 1 -0.3634 0.5151 -0.8893 35 1 1.6452 -1.7395 -1.2685 36 1 1.7157 -0.1876 -2.1398 37 1 5.2169 0.6178 -1.2072 38 1 3.8058 1.1512 -2.1520 39 1 3.7575 1.2040 -0.3735 40 1 5.1121 -1.4961 0.1097 41 1 3.6374 -2.4924 0.0848 42 1 3.8539 -0.6089 3.3062 43 1 3.5402 -2.2521 2.6979 44 1 5.2931 -3.5317 1.6148 45 1 7.7152 -3.9056 1.3760 46 1 9.9055 -2.8876 1.1318 47 1 10.2191 -1.2444 1.7398 48 1 9.6543 -2.9160 3.9449 49 1 11.9207 -2.9239 5.4031 50 1 11.6062 -4.5674 4.7961 51 1 17.4136 -5.0399 5.6713 52 1 8.4668 0.0314 2.8333 53 1 6.0444 0.4090 3.0625 54 1 1.6906 -0.2016 2.1389 55 1 1.6648 -1.7461 1.2548 RHF calculation, no. of doubly occupied orbitals= 69 REFERENCES FOR PARAMETERS IN GAS-PHASE HAMILTONIAN: H: (AM1): M.J.S. DEWAR ET AL, J. AM. CHEM. SOC. 107 3902-3909 (1985) C: (AM1): M.J.S. DEWAR ET AL, J. AM. CHEM. SOC. 107 3902-3909 (1985) N: (AM1): M.J.S. DEWAR ET AL, J. AM. CHEM. SOC. 107 3902-3909 (1985) O: (AM1): M.J.S. DEWAR ET AL, J. AM. CHEM. SOC. 107 3902-3909 (1985) Si: (AM1): M.J.S.DEWAR, C. JIE, ORGANOMETALLICS, 6, 1486-1490 (1987). S: (AM1): M.J.S. DEWAR, Y.-C. YUAN, INORGANIC CHEM., 29, 589 (1990) REFERENCE FOR CHARGE MODEL 2: J. Li, J. Xing, C. J. Cramer, and D. G. Truhlar, J. Chem. Phys. 111 (1999) 885. REFERENCE FOR THE PARAMETERIZATION OF THE SM5.42R SOLVATION MODEL: J. Li, T. Zhu, G. D. Hawkins, P. Winget, D. A. Liotard, C. J. Cramer, and D. G. Truhlar, Theor. Chem. Acc. 103 (1999) 9-63 P. Winget, J. D. Thompson C. J. Cramer,and D. G. Truhlar, J. Phys. Chem. B. submitted. CHARGE=-1 AM1 1SCF TLIMIT=15 GEO-OK SM5.42R & SOLVNT=WATER ZINC000040541075.mol2 55 1SCF WAS SPECIFIED, SO GEOMETRY OPTIMIZATION WAS NOT USED SCF FIELD WAS ACHIEVED Wall clock time and date at job start Tue Mar 31 2020 06:55:07 Heat of formation + Delta-G solvation = -47.768805 kcal Electronic energy + Delta-G solvation = -30850.517616 eV Core-core repulsion = 26783.558396 eV Total energy + Delta-G solvation = -4066.959220 eV No. of doubly occupied orbitals = 69 Molecular weight (most abundant/longest-lived isotopes) = 376.193 amu Computer time = 1.41 seconds Orbital eigenvalues (eV) -41.20663 -40.61223 -39.73734 -36.54559 -35.26920 -34.58196 -34.01292 -32.69897 -31.89126 -30.85461 -28.36340 -27.75030 -27.61301 -27.38278 -25.67010 -23.68733 -23.35266 -22.45880 -21.81171 -21.38295 -19.87865 -19.60397 -18.01747 -17.54278 -17.11407 -16.91434 -16.87790 -16.67912 -16.26047 -16.10190 -15.79930 -15.72860 -15.43392 -15.25477 -14.85141 -14.68767 -14.48109 -14.40366 -14.32403 -14.15407 -13.80999 -13.65697 -13.42807 -13.24818 -13.16389 -12.94125 -12.88252 -12.82166 -12.75008 -12.60088 -12.41652 -12.36861 -11.95404 -11.91070 -11.80629 -11.72382 -11.38156 -11.14081 -11.13937 -11.05898 -10.96957 -10.27981 -10.16631 -9.82369 -9.68850 -9.15185 -8.66627 -8.34487 -6.12645 0.19709 0.48423 1.27965 1.42740 1.47768 1.58310 1.59897 2.25883 2.29412 2.76236 2.99792 3.16857 3.33487 3.60090 3.77108 3.78970 3.84629 3.94454 3.98457 4.01294 4.11199 4.17655 4.19852 4.30294 4.33772 4.49926 4.50883 4.52578 4.53238 4.61609 4.65618 4.69781 4.71794 4.77933 4.81539 4.85112 4.89005 4.92226 4.94852 5.03651 5.08246 5.15697 5.18972 5.24260 5.32882 5.36392 5.40514 5.42098 5.43509 5.45343 5.63666 5.64316 5.65945 6.01946 6.12682 6.19691 6.20050 6.47937 7.06876 7.21387 8.74830 Molecular weight = 376.19amu Principal moments of inertia in cm(-1) A = 0.027349 B = 0.001272 C = 0.001241 Principal moments of inertia in units of 10**(-40)*gram-cm**2 A = 1023.564419 B =22011.592357 C =22557.503384 Net atomic charges, atomic populations, and dipole contributions calculated with CM2 Atom NO. Type Charge No. of electrons 1 C -0.144 4.144 2 C -0.087 4.087 3 H 0.075 0.925 4 C -0.109 4.109 5 C -0.091 4.091 6 H 0.071 0.929 7 C -0.133 4.133 8 C 0.060 3.940 9 N -0.533 5.533 10 C 0.095 3.905 11 C -0.075 4.075 12 C -0.116 4.116 13 C -0.105 4.105 14 C -0.107 4.107 15 C 0.164 3.836 16 N -0.708 5.708 17 C 0.534 3.466 18 O -0.565 6.565 19 C -0.129 4.129 20 S -0.150 6.150 21 C -0.548 4.548 22 H 0.083 0.917 23 C 0.015 3.985 24 N -0.911 5.911 25 Si 0.998 3.002 26 H -0.268 1.268 27 H -0.277 1.277 28 H -0.258 1.258 29 C -0.104 4.104 30 C -0.102 4.102 31 C 0.061 3.939 32 H 0.060 0.940 33 H 0.053 0.947 34 H 0.059 0.941 35 H 0.057 0.943 36 H 0.067 0.933 37 H 0.040 0.960 38 H 0.050 0.950 39 H 0.063 0.937 40 H 0.071 0.929 41 H 0.028 0.972 42 H 0.093 0.907 43 H 0.047 0.953 44 H 0.131 0.869 45 H 0.128 0.872 46 H 0.067 0.933 47 H 0.068 0.932 48 H 0.414 0.586 49 H 0.110 0.890 50 H 0.109 0.891 51 H 0.271 0.729 52 H 0.129 0.871 53 H 0.137 0.863 54 H 0.080 0.920 55 H 0.031 0.969 For the charges calculated by CM2: Dipole moment (debyes) X Y Z Total from point charges -38.243 9.713 -9.263 40.529 Note: The Mulliken population analysis charges presented below were not used in the solvation calculation but are provided for completeness. The chosen solvation model uses CM2 partial charges for calculating solvation energies. Net atomic charges, atomic populations, and dipole contributions using Mulliken population analysis Atom NO. Type Charge No. of electrons 1 C -0.201 4.201 2 C -0.106 4.106 3 H 0.093 0.907 4 C -0.146 4.146 5 C -0.110 4.110 6 H 0.089 0.911 7 C -0.190 4.190 8 C -0.068 4.068 9 N -0.257 5.257 10 C -0.032 4.032 11 C -0.076 4.076 12 C -0.134 4.134 13 C -0.123 4.123 14 C -0.108 4.108 15 C 0.041 3.959 16 N -0.362 5.362 17 C 0.320 3.680 18 O -0.443 6.443 19 C -0.281 4.281 20 S 0.077 5.923 21 C -0.695 4.695 22 H 0.101 0.899 23 C -0.190 4.190 24 N -0.548 5.548 25 Si 0.820 3.180 26 H -0.193 1.193 27 H -0.203 1.203 28 H -0.182 1.182 29 C -0.123 4.123 30 C -0.121 4.121 31 C -0.066 4.066 32 H 0.079 0.921 33 H 0.072 0.928 34 H 0.078 0.922 35 H 0.076 0.924 36 H 0.086 0.914 37 H 0.059 0.941 38 H 0.069 0.931 39 H 0.082 0.918 40 H 0.090 0.910 41 H 0.046 0.954 42 H 0.111 0.889 43 H 0.065 0.935 44 H 0.148 0.852 45 H 0.146 0.854 46 H 0.086 0.914 47 H 0.086 0.914 48 H 0.251 0.749 49 H 0.128 0.872 50 H 0.128 0.872 51 H 0.080 0.920 52 H 0.147 0.853 53 H 0.155 0.845 54 H 0.099 0.901 55 H 0.050 0.950 Dipole moment (debyes) X Y Z Total from point charges -36.702 10.525 -10.903 39.708 hybrid contribution -0.492 -1.612 2.040 2.646 sum -37.195 8.913 -8.863 39.261 Atomic orbital electron populations 1.21771 0.94177 1.01923 1.02268 1.21158 0.95576 1.00032 0.93785 0.90662 1.21668 0.94473 1.00380 0.98126 1.21183 0.95934 0.97214 0.96636 0.91113 1.21675 0.99812 0.95923 1.01594 1.22183 1.00070 0.94345 0.90228 1.62031 1.08288 1.53800 1.01566 1.21093 0.89915 0.99186 0.92958 1.19891 0.95589 0.93780 0.98306 1.21166 0.95219 0.97297 0.99730 1.21165 0.93184 0.98764 0.99206 1.19714 0.93448 0.95404 1.02250 1.20155 0.90163 0.99052 0.86491 1.45836 1.07538 1.65279 1.17560 1.20074 0.82447 0.77084 0.88355 1.90692 1.58638 1.53835 1.41169 1.23375 1.00976 1.04956 0.98759 1.85567 1.01448 1.83332 1.21934 1.23214 0.97698 1.48964 0.99673 0.89933 1.26116 0.94801 0.95355 1.02738 1.70185 1.01649 1.46218 1.36728 0.84958 0.77801 0.78549 0.76700 1.19291 1.20254 1.18215 1.21227 0.96231 0.96601 0.98203 1.21149 0.92239 0.99287 0.99408 1.22187 0.86330 0.99027 0.99097 0.92129 0.92769 0.92154 0.92380 0.91438 0.94104 0.93075 0.91777 0.91022 0.95355 0.88912 0.93515 0.85154 0.85392 0.91419 0.91398 0.74917 0.87226 0.87231 0.91976 0.85328 0.84532 0.90149 0.95048 Number of geometries 1 Number of calculations of the screened coulomb radii 1 The total number of SCF iterations 15. Note: The number of geometries may not correspond to the number of cycles due to rejected geometry changes. In the following table subtotal= G_P + SS G_CDS. Atom Chem. CM2 G_P Area Sigma k SS G_CDS Subtotal M number symbol chg. (kcal) (Ang**2) cal/(Ang**2) (kcal) (kcal) value 1 C -0.14 -0.95 9.20 71.98 0.66 -0.29 16 2 C -0.09 -0.76 2.53 -10.74 -0.03 -0.79 16 3 H 0.08 0.79 6.58 -2.38 -0.02 0.77 16 4 C -0.11 -1.03 4.79 30.68 0.15 -0.88 16 5 C -0.09 -1.05 3.21 -10.74 -0.03 -1.08 16 6 H 0.07 0.81 8.14 -2.39 -0.02 0.79 16 7 C -0.13 -1.66 8.75 71.98 0.63 -1.03 16 8 C 0.06 0.74 4.02 86.32 0.35 1.09 16 9 N -0.53 -6.11 4.08 -900.92 -3.68 -9.79 16 10 C 0.10 1.03 5.43 85.56 0.46 1.50 16 11 C -0.08 -1.01 4.11 -19.87 -0.08 -1.09 16 12 C -0.12 -1.62 7.82 22.27 0.17 -1.45 16 13 C -0.10 -1.72 9.70 22.27 0.22 -1.50 16 14 C -0.11 -1.96 5.25 -19.86 -0.10 -2.07 16 15 C 0.16 3.86 5.80 85.63 0.50 4.36 16 16 N -0.71 -18.50 5.55 -466.79 -2.59 -21.09 16 17 C 0.53 19.96 7.85 87.66 0.69 20.65 16 18 O -0.57 -26.45 15.86 -3.01 -0.05 -26.50 16 19 C -0.13 -5.18 6.16 71.24 0.44 -4.74 16 20 S -0.15 -8.39 20.57 -56.49 -1.16 -9.55 16 21 C -0.55 -31.44 9.50 67.96 0.65 -30.79 16 22 H 0.08 4.40 7.80 -2.91 -0.02 4.37 16 23 C 0.01 0.84 5.49 84.86 0.47 1.30 16 24 N -0.91 -56.21 13.22 21.65 0.29 -55.92 16 25 Si 1.00 43.67 29.55 68.60 2.03 45.69 16 26 H -0.27 -11.24 7.11 99.48 0.71 -10.53 16 27 H -0.28 -11.81 7.11 99.48 0.71 -11.11 16 28 H -0.26 -10.60 7.11 99.48 0.71 -9.89 16 29 C -0.10 -1.73 9.70 22.27 0.22 -1.51 16 30 C -0.10 -1.47 9.70 22.27 0.22 -1.26 16 31 C 0.06 0.58 4.71 86.32 0.41 0.98 16 32 H 0.06 0.35 8.14 -2.39 -0.02 0.33 16 33 H 0.05 0.36 8.14 -2.39 -0.02 0.34 16 34 H 0.06 0.37 8.14 -2.38 -0.02 0.35 16 35 H 0.06 0.56 8.14 -2.39 -0.02 0.54 16 36 H 0.07 0.60 8.14 -2.39 -0.02 0.58 16 37 H 0.04 0.59 8.14 -2.39 -0.02 0.57 16 38 H 0.05 0.57 8.14 -2.39 -0.02 0.55 16 39 H 0.06 0.87 6.01 -2.39 -0.01 0.86 16 40 H 0.07 1.09 5.65 -2.39 -0.01 1.08 16 41 H 0.03 0.36 8.14 -2.39 -0.02 0.34 16 42 H 0.09 0.88 8.09 -2.38 -0.02 0.86 16 43 H 0.05 0.48 8.02 -2.38 -0.02 0.46 16 44 H 0.13 1.49 8.06 -2.91 -0.02 1.47 16 45 H 0.13 1.97 8.06 -2.91 -0.02 1.95 16 46 H 0.07 1.70 8.09 -2.39 -0.02 1.68 16 47 H 0.07 1.71 8.08 -2.39 -0.02 1.69 16 48 H 0.41 8.42 8.46 -92.71 -0.78 7.64 16 49 H 0.11 3.95 8.14 -2.39 -0.02 3.93 16 50 H 0.11 3.94 8.14 -2.39 -0.02 3.92 16 51 H 0.27 15.50 8.31 -92.71 -0.77 14.73 16 52 H 0.13 2.01 8.06 -2.91 -0.02 1.98 16 53 H 0.14 1.60 8.06 -2.91 -0.02 1.58 16 54 H 0.08 0.67 8.12 -2.39 -0.02 0.65 16 55 H 0.03 0.31 8.14 -2.39 -0.02 0.29 16 Total: -1.00 -73.85 447.03 0.88 -72.98 By element: Atomic # 1 Polarization: 22.69 SS G_CDS: 0.08 Total: 22.77 kcal Atomic # 6 Polarization: -24.55 SS G_CDS: 5.97 Total: -18.59 kcal Atomic # 7 Polarization: -80.82 SS G_CDS: -5.98 Total: -86.80 kcal Atomic # 8 Polarization: -26.45 SS G_CDS: -0.05 Total: -26.50 kcal Atomic # 14 Polarization: 43.67 SS G_CDS: 2.03 Total: 45.69 kcal Atomic # 16 Polarization: -8.39 SS G_CDS: -1.16 Total: -9.55 kcal Total: -73.85 0.88 -72.98 kcal The number of atoms in the molecule is 55 The average number of expansion shells was 16.00 The maximum number of expansion shells was 16 The minimum number of expansion shells was 16 **** NOTA BENE **** This is the net solvation energy for this exact molecular structure (nuclear and electronic)! The standard-state solvation energy should be obtained as the difference between the heat of formation plus delta-G solvation for the relaxed solvated system and that for the relaxed gas-phase system. ZINC000040541075.mol2 55 1SCF run This is a breakdown of the solvation energy calculated without geometric relaxation in solution: (1) E-EN(sol) electronic-nuclear energy of solute 25.208 kcal (2) G-P(sol) polarization free energy of solvation -73.852 kcal (3) G-ENP(sol) elect.-nuc.-pol. free energy of system -48.644 kcal (4) G-CDS(sol) cavity-dispersion-solvent structure free energy 0.875 kcal (5) G-P-CDS(sol) = G-P(sol) + G-CDS(sol) = (2) + (4) -72.977 kcal (6) G-S(sol) free energy of system = (1) + (5) -47.769 kcal 1SCF WAS SPECIFIED, SO GEOMETRY OPTIMIZATION WAS NOT USED Total computer time = 1.41 seconds