Wall clock time and date at job start Tue Mar 31 2020 21:17:52 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 * DEV - DEVELOPER OPTIONS ARE ALLOWED * SM5.42R - SM5.42R CALCULATIONS WILL BE PERFORMED * - CHARGE MODEL 2 WILL BE USED (CM2A) * - THE SOLVENT IS USER-SPECIFIED * DIELEC - THE SOLVENT DIELECTRIC CONSTANT IS 2.06 * IOFR - THE SOLVENT INDEX OF REFRACTION IS 1.4345 * ALPHA - THE SOLVENT ALPHA IS 0.00 * BETA - THE SOLVENT BETA IS 0.00 * GAMMA - THE SOLVENT MACROSCOPIC SURFACE TENSION IS * 38.93 CAL MOL^-1 ANGSTROM^-2 * FACARB - THE FRACTION OF AROMATIC CARBONS IS 0.00 * FEHALO - THE FRACTION OF ELECTRONEGATIVE HALOGENS IS 0.00 ******************************************************************************* 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 1.30997 * 1 3 3 C 1.50704 * 119.99935 * 2 1 4 4 H 1.08996 * 109.87097 * 358.99513 * 3 2 1 5 5 O 1.43740 * 109.88021 * 237.83030 * 3 2 1 6 6 C 1.44382 * 106.97657 * 267.08878 * 5 3 2 7 7 C 1.55222 * 103.56840 * 320.01558 * 6 5 3 8 8 C 1.54106 * 109.87597 * 119.99790 * 3 2 1 9 9 H 1.08996 * 110.48665 * 358.58743 * 8 3 2 10 10 C 1.50691 * 110.48858 * 236.07065 * 8 3 2 11 11 O 1.21278 * 120.00299 * 1.84680 * 10 8 3 12 12 N 1.34775 * 120.00181 * 181.84727 * 10 8 3 13 13 C 1.46923 * 120.63354 * 180.02562 * 12 10 8 14 14 C 1.53195 * 108.77800 * 126.36748 * 13 12 10 15 15 C 1.53041 * 109.33975 * 54.62101 * 14 13 12 16 16 C 1.53001 * 109.45954 * 178.63180 * 15 14 13 17 17 N 1.46497 * 109.47102 * 184.21611 * 16 15 14 18 18 C 1.36933 * 120.00091 * 264.16855 * 17 16 15 19 19 H 1.07997 * 120.00309 * 9.22193 * 18 17 16 20 20 C 1.38815 * 120.00060 * 189.22748 * 18 17 16 21 21 N 1.31616 * 119.99914 * 26.77150 * 20 18 17 22 22 Si 1.86800 * 119.99945 * 206.77528 * 20 18 17 23 23 H 1.48503 * 109.47319 * 94.98788 * 22 20 18 24 24 H 1.48501 * 109.47151 * 214.98721 * 22 20 18 25 25 H 1.48504 * 109.47180 * 334.98864 * 22 20 18 26 26 C 1.46499 * 119.99860 * 84.16266 * 17 16 15 27 27 C 1.53000 * 109.46817 * 84.18198 * 26 17 16 28 28 C 1.53041 * 109.53351 * 298.68399 * 15 14 13 29 29 C 1.46926 * 120.63022 * 359.97438 * 12 10 8 30 30 H 1.07999 * 119.99979 * 179.97438 * 1 2 3 31 31 H 1.07998 * 120.00043 * 0.02562 * 1 2 3 32 32 H 1.07994 * 120.00401 * 180.02562 * 2 1 3 33 33 H 1.09000 * 110.61342 * 78.44301 * 6 5 3 34 34 H 1.08998 * 110.61919 * 201.27753 * 6 5 3 35 35 H 1.09005 * 110.89006 * 278.74454 * 7 6 5 36 36 H 1.08996 * 111.02530 * 155.07214 * 7 6 5 37 37 H 1.09002 * 109.59079 * 6.57676 * 13 12 10 38 38 H 1.09007 * 109.70331 * 246.22660 * 13 12 10 39 39 H 1.08999 * 109.49563 * 174.58487 * 14 13 12 40 40 H 1.08996 * 109.49519 * 294.64740 * 14 13 12 41 41 H 1.08993 * 109.46346 * 58.66792 * 15 14 13 42 42 H 1.08994 * 109.47224 * 304.21729 * 16 15 14 43 43 H 1.09000 * 109.47055 * 64.21755 * 16 15 14 44 44 H 0.97004 * 119.99451 * 180.02562 * 21 20 18 45 45 H 1.08999 * 109.47129 * 204.18000 * 26 17 16 46 46 H 1.08990 * 109.47474 * 324.18172 * 26 17 16 47 47 H 1.08998 * 109.47521 * 302.22903 * 27 26 17 48 48 H 1.08999 * 109.47216 * 62.23315 * 27 26 17 49 49 H 1.09000 * 109.47174 * 182.22437 * 27 26 17 50 50 H 1.09010 * 109.47167 * 301.36441 * 28 15 14 51 51 H 1.09006 * 109.52275 * 181.30877 * 28 15 14 52 52 H 1.09004 * 109.58671 * 353.42292 * 29 12 10 53 53 H 1.08997 * 109.58573 * 113.84300 * 29 12 10 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 1.3100 0.0000 0.0000 3 6 2.0635 1.3051 0.0000 4 1 1.3611 2.1384 -0.0180 5 8 2.9312 1.3686 -1.1442 6 6 4.2186 0.8670 -0.7253 7 6 4.3957 1.4616 0.6975 8 6 2.9530 1.3966 1.2551 9 1 2.8246 0.5121 1.8789 10 6 2.6334 2.6437 2.0383 11 8 1.7516 3.3867 1.6624 12 7 3.3276 2.9336 3.1566 13 6 3.0273 4.1455 3.9311 14 6 2.7704 3.7484 5.3882 15 6 3.9637 2.9468 5.9130 16 6 3.7250 2.5780 7.3786 17 7 4.9091 1.8985 7.9102 18 6 4.9616 0.5304 7.9313 19 1 4.2028 -0.0471 7.4244 20 6 5.9903 -0.1144 8.6045 21 7 6.5852 0.4769 9.6188 22 14 6.5302 -1.8211 8.0707 23 1 7.6845 -1.7077 7.1433 24 1 6.9296 -2.6097 9.2639 25 1 5.4058 -2.5028 7.3805 26 6 6.0369 2.6829 8.4192 27 6 5.7691 3.0771 9.8730 28 6 4.1263 1.6699 5.0852 29 6 4.3983 2.0431 3.6250 30 1 -0.5400 -0.9353 -0.0004 31 1 -0.5400 0.9353 -0.0004 32 1 1.8500 -0.9352 -0.0004 33 1 4.2118 -0.2223 -0.6861 34 1 5.0042 1.2209 -1.3929 35 1 4.7471 2.4922 0.6471 36 1 5.0718 0.8505 1.2954 37 1 2.1404 4.6299 3.5225 38 1 3.8732 4.8314 3.8829 39 1 2.6412 4.6463 5.9925 40 1 1.8688 3.1386 5.4455 41 1 4.8689 3.5486 5.8330 42 1 3.5363 3.4835 7.9551 43 1 2.8628 1.9151 7.4507 44 1 7.3043 0.0264 10.0889 45 1 6.9476 2.0863 8.3663 46 1 6.1562 3.5821 7.8150 47 1 4.8375 3.6400 9.9312 48 1 5.6893 2.1782 10.4844 49 1 6.5898 3.6938 10.2394 50 1 3.2122 1.0790 5.1453 51 1 4.9619 1.0878 5.4738 52 1 4.4160 1.1403 3.0144 53 1 5.3577 2.5552 3.5515 RHF calculation, no. of doubly occupied orbitals= 65 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). 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=GENORG IOFR=1.4345 ALPHA=0.00 BETA=0.00 GAMMA=38.93 & DIELEC=2.06 FACARB=0.00 FEHALO=0.00 DEV ZINC001717356673.mol2 53 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 21:17:52 Heat of formation + Delta-G solvation = -35.827669 kcal Electronic energy + Delta-G solvation = -30886.693545 eV Core-core repulsion = 26952.633734 eV Total energy + Delta-G solvation = -3934.059811 eV No. of doubly occupied orbitals = 65 Molecular weight (most abundant/longest-lived isotopes) = 336.220 amu Computer time = 1.34 seconds Orbital eigenvalues (eV) -40.92930 -39.13294 -37.62236 -35.86672 -33.94934 -33.57568 -32.41849 -30.92133 -30.74851 -29.18736 -28.76597 -26.77548 -24.44299 -23.72222 -22.90162 -22.71351 -22.00964 -20.63577 -20.15601 -19.58828 -18.81724 -17.37893 -16.81697 -16.64007 -16.15685 -15.92133 -15.22951 -15.09050 -14.77541 -14.21904 -14.03457 -13.95534 -13.70824 -13.61269 -13.46349 -13.24197 -13.03575 -12.87782 -12.44199 -12.20175 -11.99907 -11.85443 -11.76350 -11.64196 -11.49717 -11.30814 -11.19880 -11.06373 -10.95057 -10.82070 -10.56775 -10.39988 -10.26596 -10.12778 -9.94680 -9.91155 -9.78841 -9.60305 -9.58276 -9.30493 -8.60942 -8.36647 -6.87597 -5.79611 -3.08459 1.95903 2.53129 2.93189 3.34678 3.42771 3.44855 3.77617 4.18631 4.27409 4.40991 4.47293 4.78967 4.81659 4.88665 4.92415 5.00535 5.07902 5.17890 5.24380 5.27949 5.34220 5.39686 5.42220 5.43313 5.56662 5.61701 5.64971 5.66855 5.76333 5.81275 5.88764 6.08223 6.10174 6.24315 6.33569 6.40132 6.45102 6.49672 6.54759 6.55703 6.62999 6.65640 6.83966 6.92553 6.96717 7.04133 7.16675 7.38989 7.63560 7.73860 8.09375 8.10902 8.33724 9.22823 9.86817 10.33112 11.24460 Molecular weight = 336.22amu Principal moments of inertia in cm(-1) A = 0.013623 B = 0.003114 C = 0.002774 Principal moments of inertia in units of 10**(-40)*gram-cm**2 A = 2054.818572 B = 8989.794053 C =10092.873466 Net atomic charges, atomic populations, and dipole contributions calculated with CM2 Atom NO. Type Charge No. of electrons 1 C -0.167 4.167 2 C -0.179 4.179 3 C 0.114 3.886 4 H 0.120 0.880 5 O -0.363 6.363 6 C 0.045 3.955 7 C -0.146 4.146 8 C -0.137 4.137 9 H 0.113 0.887 10 C 0.526 3.474 11 O -0.547 6.547 12 N -0.602 5.602 13 C 0.113 3.887 14 C -0.128 4.128 15 C -0.105 4.105 16 C 0.157 3.843 17 N -0.597 5.597 18 C -0.246 4.246 19 H 0.073 0.927 20 C -0.002 4.002 21 N -0.893 5.893 22 Si 0.887 3.113 23 H -0.290 1.290 24 H -0.294 1.294 25 H -0.281 1.281 26 C 0.170 3.830 27 C -0.154 4.154 28 C -0.121 4.121 29 C 0.101 3.899 30 H 0.101 0.899 31 H 0.101 0.899 32 H 0.111 0.889 33 H 0.063 0.937 34 H 0.096 0.904 35 H 0.083 0.917 36 H 0.094 0.906 37 H 0.086 0.914 38 H 0.064 0.936 39 H 0.070 0.930 40 H 0.062 0.938 41 H 0.064 0.936 42 H 0.032 0.968 43 H 0.045 0.955 44 H 0.251 0.749 45 H 0.080 0.920 46 H 0.002 0.998 47 H 0.010 0.990 48 H 0.094 0.906 49 H 0.017 0.983 50 H 0.056 0.944 51 H 0.101 0.899 52 H 0.081 0.919 53 H 0.069 0.931 For the charges calculated by CM2: Dipole moment (debyes) X Y Z Total from point charges -4.882 2.455 -16.082 16.985 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 -0.204 4.204 2 C -0.197 4.197 3 C 0.056 3.944 4 H 0.138 0.862 5 O -0.282 6.282 6 C -0.032 4.032 7 C -0.183 4.183 8 C -0.159 4.159 9 H 0.131 0.869 10 C 0.313 3.687 11 O -0.425 6.425 12 N -0.334 5.334 13 C -0.009 4.009 14 C -0.166 4.166 15 C -0.126 4.126 16 C 0.029 3.971 17 N -0.318 5.318 18 C -0.375 4.375 19 H 0.091 0.909 20 C -0.199 4.199 21 N -0.539 5.539 22 Si 0.718 3.282 23 H -0.217 1.217 24 H -0.221 1.221 25 H -0.207 1.207 26 C 0.045 3.955 27 C -0.213 4.213 28 C -0.159 4.159 29 C -0.022 4.022 30 H 0.119 0.881 31 H 0.119 0.881 32 H 0.129 0.871 33 H 0.082 0.918 34 H 0.114 0.886 35 H 0.101 0.899 36 H 0.112 0.888 37 H 0.105 0.895 38 H 0.083 0.917 39 H 0.089 0.911 40 H 0.081 0.919 41 H 0.082 0.918 42 H 0.050 0.950 43 H 0.064 0.936 44 H 0.061 0.939 45 H 0.099 0.901 46 H 0.020 0.980 47 H 0.029 0.971 48 H 0.113 0.887 49 H 0.036 0.964 50 H 0.075 0.925 51 H 0.119 0.881 52 H 0.099 0.901 53 H 0.087 0.913 Dipole moment (debyes) X Y Z Total from point charges -5.271 2.856 -16.353 17.417 hybrid contribution 0.508 -1.129 0.258 1.265 sum -4.763 1.727 -16.095 16.874 Atomic orbital electron populations 1.23920 0.95810 1.02262 0.98391 1.23293 0.96508 0.98350 1.01565 1.21885 0.92176 0.96835 0.83526 0.86213 1.88972 1.21444 1.84802 1.32974 1.23625 0.86520 0.98436 0.94607 1.23306 0.94710 1.03330 0.96997 1.22670 0.96952 0.98303 0.97943 0.86939 1.20172 0.81210 0.86686 0.80591 1.90646 1.32098 1.51137 1.68643 1.48107 1.35862 1.24823 1.24624 1.21617 1.01656 0.86073 0.91533 1.21942 0.99584 1.00672 0.94435 1.21776 0.96810 0.95538 0.98483 1.20703 0.90310 0.95620 0.90430 1.44156 1.14065 1.02635 1.70938 1.19239 1.09293 0.81724 1.27242 0.90897 1.24679 1.01037 0.97481 0.96718 1.70155 1.26919 1.38202 1.18581 0.86478 0.78894 0.84804 0.78062 1.21731 1.22125 1.20683 1.20653 0.92240 0.91635 0.90951 1.22373 0.96138 1.01423 1.01376 1.21925 1.03676 0.98502 0.91844 1.22069 0.89550 0.93338 0.97215 0.88050 0.88119 0.87146 0.91843 0.88602 0.89857 0.88782 0.89524 0.91725 0.91107 0.91909 0.91804 0.94982 0.93606 0.93885 0.90137 0.98026 0.97105 0.88702 0.96382 0.92513 0.88072 0.90108 0.91320 Number of geometries 1 Number of calculations of the screened coulomb radii 1 The total number of SCF iterations 21. 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 -0.17 -1.58 14.32 29.02 0.42 -1.17 16 2 C -0.18 -1.82 8.87 -36.02 -0.32 -2.14 16 3 C 0.11 1.33 3.45 -27.30 -0.09 1.23 16 4 H 0.12 1.64 6.11 -51.93 -0.32 1.32 16 5 O -0.36 -4.40 11.18 -35.23 -0.39 -4.79 16 6 C 0.04 0.39 7.66 38.33 0.29 0.68 16 7 C -0.15 -1.29 5.43 -24.60 -0.13 -1.43 16 8 C -0.14 -1.49 2.11 -90.24 -0.19 -1.68 16 9 H 0.11 1.12 7.23 -51.93 -0.38 0.74 16 10 C 0.53 7.12 6.97 -10.99 -0.08 7.05 16 11 O -0.55 -9.04 14.67 5.56 0.08 -8.96 16 12 N -0.60 -7.68 2.97 -172.80 -0.51 -8.20 16 13 C 0.11 1.44 6.43 -3.71 -0.02 1.41 16 14 C -0.13 -1.68 5.36 -26.61 -0.14 -1.82 16 15 C -0.10 -1.61 2.36 -90.58 -0.21 -1.82 16 16 C 0.16 2.94 5.16 -4.04 -0.02 2.92 16 17 N -0.60 -13.47 2.29 -173.25 -0.40 -13.87 16 18 C -0.25 -6.10 8.00 -15.06 -0.12 -6.22 16 19 H 0.07 1.79 7.96 -52.49 -0.42 1.37 16 20 C 0.00 -0.05 4.83 -17.43 -0.08 -0.13 16 21 N -0.89 -23.95 8.63 55.49 0.48 -23.47 16 22 Si 0.89 20.37 29.63 -169.99 -5.04 15.33 16 23 H -0.29 -6.68 7.11 56.52 0.40 -6.28 16 24 H -0.29 -6.99 7.11 56.52 0.40 -6.59 16 25 H -0.28 -6.34 7.11 56.52 0.40 -5.94 16 26 C 0.17 3.88 5.62 -4.04 -0.02 3.85 16 27 C -0.15 -3.46 9.79 37.16 0.36 -3.09 16 28 C -0.12 -1.81 5.00 -26.63 -0.13 -1.94 16 29 C 0.10 1.20 5.70 -3.73 -0.02 1.18 16 30 H 0.10 0.78 8.06 -52.49 -0.42 0.36 16 31 H 0.10 0.97 7.85 -52.49 -0.41 0.55 16 32 H 0.11 0.98 8.06 -52.49 -0.42 0.56 16 33 H 0.06 0.47 8.14 -51.93 -0.42 0.05 16 34 H 0.10 0.69 8.14 -51.93 -0.42 0.27 16 35 H 0.08 0.80 7.86 -51.93 -0.41 0.39 16 36 H 0.09 0.67 6.95 -51.93 -0.36 0.31 16 37 H 0.09 1.16 7.01 -51.93 -0.36 0.80 16 38 H 0.06 0.77 8.14 -51.92 -0.42 0.34 16 39 H 0.07 0.86 8.14 -51.93 -0.42 0.44 16 40 H 0.06 0.87 8.14 -51.93 -0.42 0.44 16 41 H 0.06 1.03 8.00 -51.93 -0.42 0.62 16 42 H 0.03 0.59 8.01 -51.93 -0.42 0.18 16 43 H 0.05 0.88 7.99 -51.93 -0.42 0.47 16 44 H 0.25 6.63 8.31 -40.82 -0.34 6.29 16 45 H 0.08 2.04 5.99 -51.93 -0.31 1.73 16 46 H 0.00 0.03 7.98 -51.93 -0.41 -0.38 16 47 H 0.01 0.21 8.03 -51.93 -0.42 -0.20 16 48 H 0.09 2.43 6.10 -51.93 -0.32 2.12 16 49 H 0.02 0.36 8.14 -51.93 -0.42 -0.06 16 50 H 0.06 0.88 8.14 -51.92 -0.42 0.45 16 51 H 0.10 1.78 6.56 -51.93 -0.34 1.44 16 52 H 0.08 0.82 4.47 -51.93 -0.23 0.59 16 53 H 0.07 0.79 8.14 -51.93 -0.42 0.37 16 LS Contribution 401.42 15.07 6.05 6.05 Total: -1.00 -28.71 401.42 -9.55 -38.26 By element: Atomic # 1 Polarization: 12.05 SS G_CDS: -9.30 Total: 2.75 kcal Atomic # 6 Polarization: -2.58 SS G_CDS: -0.52 Total: -3.10 kcal Atomic # 7 Polarization: -45.10 SS G_CDS: -0.43 Total: -45.53 kcal Atomic # 8 Polarization: -13.44 SS G_CDS: -0.31 Total: -13.75 kcal Atomic # 14 Polarization: 20.37 SS G_CDS: -5.04 Total: 15.33 kcal Total LS contribution 6.05 Total: 6.05 kcal Total: -28.71 -9.55 -38.26 kcal The number of atoms in the molecule is 53 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. ZINC001717356673.mol2 53 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 2.431 kcal (2) G-P(sol) polarization free energy of solvation -28.707 kcal (3) G-ENP(sol) elect.-nuc.-pol. free energy of system -26.276 kcal (4) G-CDS(sol) cavity-dispersion-solvent structure free energy -9.551 kcal (5) G-P-CDS(sol) = G-P(sol) + G-CDS(sol) = (2) + (4) -38.258 kcal (6) G-S(sol) free energy of system = (1) + (5) -35.828 kcal 1SCF WAS SPECIFIED, SO GEOMETRY OPTIMIZATION WAS NOT USED Total computer time = 1.35 seconds