Wall clock time and date at job start Sat Apr 11 2020 08:00:02 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 N 2 2 C 1.31614 * 1 3 3 Si 1.86801 * 119.99833 * 2 1 4 4 H 1.48496 * 109.47031 * 239.99727 * 3 2 1 5 5 H 1.48497 * 109.47267 * 359.97438 * 3 2 1 6 6 H 1.48504 * 109.47169 * 120.00009 * 3 2 1 7 7 C 1.38811 * 120.00467 * 179.97438 * 2 1 3 8 8 H 1.08002 * 120.00530 * 180.02562 * 7 2 1 9 9 N 1.36943 * 119.99622 * 359.72375 * 7 2 1 10 10 C 1.46504 * 119.99781 * 180.27904 * 9 7 2 11 11 C 1.52996 * 109.46681 * 180.02562 * 10 9 7 12 12 H 1.08994 * 109.50117 * 54.93356 * 11 10 9 13 13 C 1.53039 * 109.49990 * 294.83199 * 11 10 9 14 14 C 1.53037 * 109.54095 * 178.68556 * 13 11 10 15 15 C 1.53195 * 109.31112 * 61.36908 * 14 13 11 16 16 N 1.46925 * 108.77414 * 305.36363 * 15 14 13 17 17 C 1.34776 * 120.63017 * 233.63089 * 16 15 14 18 18 O 1.21280 * 119.99735 * 179.97438 * 17 16 15 19 19 C 1.50698 * 120.00231 * 359.97438 * 17 16 15 20 20 C 1.52995 * 109.47310 * 179.97438 * 19 17 16 21 21 C 1.52998 * 109.47120 * 180.02562 * 20 19 17 22 22 O 1.42903 * 109.47237 * 180.02562 * 21 20 19 23 23 C 1.35902 * 117.00150 * 180.02562 * 22 21 20 24 24 C 1.38739 * 120.05514 * 359.72156 * 23 22 21 25 25 C 1.38142 * 119.94217 * 179.74888 * 24 23 22 26 26 C 1.38271 * 120.05436 * 0.50484 * 25 24 23 27 27 C 1.38258 * 120.10941 * 359.76966 * 26 25 24 28 28 C 1.38142 * 120.05988 * 359.97438 * 27 26 25 29 29 C 1.46925 * 118.73947 * 53.61274 * 16 15 14 30 30 H 0.96995 * 120.00147 * 0.02562 * 1 2 3 31 31 H 0.97000 * 119.99808 * 0.27579 * 9 7 2 32 32 H 1.09006 * 109.46810 * 299.99903 * 10 9 7 33 33 H 1.08997 * 109.47198 * 60.00005 * 10 9 7 34 34 H 1.09000 * 109.46313 * 298.71429 * 13 11 10 35 35 H 1.08999 * 109.45485 * 58.66524 * 13 11 10 36 36 H 1.08996 * 109.50017 * 301.41595 * 14 13 11 37 37 H 1.09002 * 109.52437 * 181.33574 * 14 13 11 38 38 H 1.08998 * 109.58425 * 185.57588 * 15 14 13 39 39 H 1.08996 * 109.70585 * 65.22273 * 15 14 13 40 40 H 1.08999 * 109.47425 * 300.00336 * 19 17 16 41 41 H 1.09010 * 109.46670 * 60.00299 * 19 17 16 42 42 H 1.08994 * 109.47859 * 300.00545 * 20 19 17 43 43 H 1.09000 * 109.46872 * 60.00834 * 20 19 17 44 44 H 1.08999 * 109.47442 * 300.00557 * 21 20 19 45 45 H 1.08997 * 109.47129 * 60.00644 * 21 20 19 46 46 H 1.08000 * 120.02504 * 359.97438 * 24 23 22 47 47 H 1.08001 * 119.96864 * 180.23395 * 25 24 23 48 48 H 1.08001 * 119.93888 * 179.74807 * 26 25 24 49 49 H 1.08001 * 119.96931 * 179.97438 * 27 26 25 50 50 H 1.08001 * 120.02688 * 180.02562 * 28 27 26 51 51 H 1.09002 * 109.58728 * 186.60350 * 29 16 15 52 52 H 1.08995 * 109.59198 * 66.17205 * 29 16 15 Note: An asterisk (*) indicates this parameter was or will be optimized. Cartesian coordinates (angstroms) NO. Atom X Y Z 1 7 0.0000 0.0000 0.0000 2 6 1.3161 0.0000 0.0000 3 14 2.2501 1.6178 0.0000 4 1 3.1039 1.6964 -1.2124 5 1 1.2851 2.7465 -0.0006 6 1 3.1039 1.6965 1.2125 7 6 2.0103 -1.2021 0.0005 8 1 3.0903 -1.2021 0.0010 9 7 1.3256 -2.3880 0.0068 10 6 2.0582 -3.6567 0.0135 11 6 1.0640 -4.8196 0.0190 12 1 0.3792 -4.7168 -0.8228 13 6 0.2710 -4.8076 1.3279 14 6 -0.7465 -5.9507 1.3204 15 6 -0.0057 -7.2876 1.2163 16 7 0.8706 -7.2521 0.0376 17 6 0.7998 -8.2176 -0.9001 18 8 1.5284 -8.1767 -1.8688 19 6 -0.1846 -9.3481 -0.7448 20 6 -0.0617 -10.2988 -1.9371 21 6 -1.0615 -11.4461 -1.7797 22 8 -0.9463 -12.3345 -2.8931 23 6 -1.7708 -13.4148 -2.9084 24 6 -2.6682 -13.6187 -1.8702 25 6 -3.5088 -14.7147 -1.8907 26 6 -3.4491 -15.6137 -2.9396 27 6 -2.5517 -15.4157 -3.9725 28 6 -1.7126 -14.3184 -3.9594 29 6 1.8253 -6.1438 -0.0998 30 1 -0.4850 0.8400 -0.0004 31 1 0.3556 -2.3880 0.0068 32 1 2.6849 -3.7191 -0.8762 33 1 2.6848 -3.7097 0.9038 34 1 0.9541 -4.9348 2.1676 35 1 -0.2522 -3.8564 1.4266 36 1 -1.4146 -5.8375 0.4667 37 1 -1.3273 -5.9274 2.2425 38 1 -0.7272 -8.0978 1.1110 39 1 0.5937 -7.4464 2.1127 40 1 0.0275 -9.8906 0.1765 41 1 -1.1968 -8.9454 -0.7045 42 1 -0.2740 -9.7561 -2.8581 43 1 0.9504 -10.7015 -1.9778 44 1 -0.8496 -11.9891 -0.8587 45 1 -2.0735 -11.0432 -1.7393 46 1 -2.7121 -12.9192 -1.0486 47 1 -4.2102 -14.8718 -1.0846 48 1 -4.1043 -16.4722 -2.9517 49 1 -2.5066 -16.1196 -4.7904 50 1 -1.0120 -14.1641 -4.7667 51 1 2.3120 -6.1993 -1.0736 52 1 2.5743 -6.2066 0.6895 RHF calculation, no. of doubly occupied orbitals= 66 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 ZINC001566912574.mol2 52 1SCF WAS SPECIFIED, SO GEOMETRY OPTIMIZATION WAS NOT USED SCF FIELD WAS ACHIEVED Wall clock time and date at job start Sat Apr 11 2020 08:00:02 Heat of formation + Delta-G solvation = -52.122891 kcal Electronic energy + Delta-G solvation = -29055.638294 eV Core-core repulsion = 25019.957207 eV Total energy + Delta-G solvation = -4035.681087 eV No. of doubly occupied orbitals = 66 Molecular weight (most abundant/longest-lived isotopes) = 346.204 amu Computer time = 1.19 seconds Orbital eigenvalues (eV) -40.54794 -40.23602 -38.00591 -37.63499 -34.99204 -34.19589 -32.76266 -31.72317 -31.41165 -30.36353 -29.91529 -27.80345 -25.58170 -25.19313 -23.51504 -22.84953 -22.53442 -21.91788 -21.49140 -19.95292 -19.05907 -18.48126 -17.40937 -17.01034 -16.79716 -16.46320 -16.05912 -15.78330 -15.60200 -14.82896 -14.74391 -14.43345 -14.27230 -14.13881 -13.94258 -13.80342 -13.59914 -13.32743 -13.10392 -13.04167 -12.64676 -12.60970 -12.48274 -12.10598 -11.97766 -11.87664 -11.72769 -11.70292 -11.14402 -11.06281 -10.98140 -10.90924 -10.80935 -10.63668 -10.36721 -10.20823 -10.05123 -9.80998 -9.65871 -9.41942 -8.86471 -8.61952 -8.59719 -6.91006 -5.75915 -3.04211 0.92518 1.04968 2.54119 2.63037 3.05076 3.39091 3.44977 3.49266 3.50311 4.22032 4.40558 4.47402 4.48956 4.59979 4.60435 4.67684 4.71660 4.80387 4.89393 4.92495 4.97125 4.97735 5.05222 5.10265 5.14787 5.18551 5.26506 5.33880 5.47811 5.57420 5.59261 5.59750 5.69317 5.82262 5.85030 5.85836 5.94108 5.98440 5.99865 6.07484 6.12696 6.16861 6.20875 6.37463 6.45053 6.51933 6.65335 6.79769 6.89463 7.04727 7.35127 7.70660 8.10391 8.43172 9.54342 10.12136 10.46990 11.46993 Molecular weight = 346.20amu Principal moments of inertia in cm(-1) A = 0.026690 B = 0.001443 C = 0.001432 Principal moments of inertia in units of 10**(-40)*gram-cm**2 A = 1048.822504 B =19399.609521 C =19554.341557 Net atomic charges, atomic populations, and dipole contributions calculated with CM2 Atom NO. Type Charge No. of electrons 1 N -0.935 5.935 2 C -0.014 4.014 3 Si 0.907 3.093 4 H -0.286 1.286 5 H -0.291 1.291 6 H -0.286 1.286 7 C -0.239 4.239 8 H 0.070 0.930 9 N -0.730 5.730 10 C 0.160 3.840 11 C -0.106 4.106 12 H 0.073 0.927 13 C -0.112 4.112 14 C -0.136 4.136 15 C 0.106 3.894 16 N -0.609 5.609 17 C 0.514 3.486 18 O -0.540 6.540 19 C -0.136 4.136 20 C -0.105 4.105 21 C 0.060 3.940 22 O -0.313 6.313 23 C 0.132 3.868 24 C -0.211 4.211 25 C -0.081 4.081 26 C -0.162 4.162 27 C -0.081 4.081 28 C -0.154 4.154 29 C 0.118 3.882 30 H 0.255 0.745 31 H 0.384 0.616 32 H 0.020 0.980 33 H 0.020 0.980 34 H 0.061 0.939 35 H 0.079 0.921 36 H 0.066 0.934 37 H 0.073 0.927 38 H 0.080 0.920 39 H 0.070 0.930 40 H 0.095 0.905 41 H 0.097 0.903 42 H 0.083 0.917 43 H 0.082 0.918 44 H 0.063 0.937 45 H 0.064 0.936 46 H 0.128 0.872 47 H 0.124 0.876 48 H 0.122 0.878 49 H 0.128 0.872 50 H 0.131 0.869 51 H 0.092 0.908 52 H 0.067 0.933 For the charges calculated by CM2: Dipole moment (debyes) X Y Z Total from point charges -7.641 -32.095 0.677 32.999 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 N -0.583 5.583 2 C -0.210 4.210 3 Si 0.738 3.262 4 H -0.213 1.213 5 H -0.217 1.217 6 H -0.213 1.213 7 C -0.371 4.371 8 H 0.088 0.912 9 N -0.375 5.375 10 C 0.031 3.969 11 C -0.126 4.126 12 H 0.092 0.908 13 C -0.149 4.149 14 C -0.174 4.174 15 C -0.016 4.016 16 N -0.342 5.342 17 C 0.302 3.698 18 O -0.417 6.417 19 C -0.176 4.176 20 C -0.143 4.143 21 C -0.015 4.015 22 O -0.226 6.226 23 C 0.087 3.913 24 C -0.229 4.229 25 C -0.099 4.099 26 C -0.181 4.181 27 C -0.099 4.099 28 C -0.173 4.173 29 C -0.004 4.004 30 H 0.065 0.935 31 H 0.218 0.782 32 H 0.038 0.962 33 H 0.038 0.962 34 H 0.079 0.921 35 H 0.098 0.902 36 H 0.085 0.915 37 H 0.092 0.908 38 H 0.099 0.901 39 H 0.088 0.912 40 H 0.113 0.887 41 H 0.115 0.885 42 H 0.102 0.898 43 H 0.101 0.899 44 H 0.081 0.919 45 H 0.082 0.918 46 H 0.146 0.854 47 H 0.142 0.858 48 H 0.141 0.859 49 H 0.146 0.854 50 H 0.149 0.851 51 H 0.110 0.890 52 H 0.086 0.914 Dipole moment (debyes) X Y Z Total from point charges -6.964 -31.876 0.029 32.628 hybrid contribution -0.102 1.088 0.378 1.157 sum -7.066 -30.788 0.407 31.591 Atomic orbital electron populations 1.69643 1.05105 1.25725 1.57859 1.24723 0.95519 0.97655 1.03058 0.86262 0.78516 0.83524 0.77856 1.21271 1.21703 1.21293 1.19200 0.91039 0.84187 1.42630 0.91241 1.42332 1.05806 0.99846 1.89487 1.20589 0.93033 0.85291 0.97951 1.21668 0.98356 0.94037 0.98532 0.90836 1.21530 0.97520 0.98709 0.97173 1.21950 0.98505 0.94480 1.02469 1.21801 0.93151 0.98760 0.87938 1.48141 1.38718 1.24813 1.22538 1.20457 0.84123 0.83028 0.82197 1.90719 1.43935 1.76805 1.30283 1.21545 1.00167 0.95663 1.00237 1.21241 0.99992 0.94047 0.98970 1.22849 1.00235 0.90393 0.87995 1.86086 1.57138 1.33680 1.45700 1.19067 0.90198 0.87499 0.94539 1.21301 1.00118 1.01477 1.00053 1.20975 0.97464 0.93453 0.98000 1.21079 1.00939 1.00620 0.95424 1.20990 0.94397 0.96305 0.98223 1.20503 1.02895 0.95105 0.98804 1.21657 0.90779 0.84633 1.03343 0.93512 0.78244 0.96183 0.96185 0.92061 0.90214 0.91518 0.90801 0.90139 0.91213 0.88668 0.88522 0.89788 0.89884 0.91882 0.91796 0.85422 0.85805 0.85950 0.85374 0.85133 0.88969 0.91442 Number of geometries 1 Number of calculations of the screened coulomb radii 1 The total number of SCF iterations 14. 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 N -0.93 -28.22 13.06 55.49 0.72 -27.50 16 2 C -0.01 -0.40 5.50 -17.43 -0.10 -0.49 16 3 Si 0.91 22.52 29.55 -169.99 -5.02 17.50 16 4 H -0.29 -7.02 7.11 56.52 0.40 -6.61 16 5 H -0.29 -7.26 7.11 56.52 0.40 -6.86 16 6 H -0.29 -6.97 7.11 56.52 0.40 -6.56 16 7 C -0.24 -6.74 9.99 -15.06 -0.15 -6.89 16 8 H 0.07 1.90 7.83 -52.49 -0.41 1.49 16 9 N -0.73 -18.45 5.32 -59.91 -0.32 -18.76 16 10 C 0.16 3.20 5.65 -4.04 -0.02 3.18 16 11 C -0.11 -1.71 2.37 -90.50 -0.21 -1.92 16 12 H 0.07 1.31 8.14 -51.93 -0.42 0.88 16 13 C -0.11 -1.60 5.06 -26.69 -0.13 -1.74 16 14 C -0.14 -1.44 6.08 -26.61 -0.16 -1.60 16 15 C 0.11 0.94 6.34 -3.71 -0.02 0.91 16 16 N -0.61 -7.23 2.97 -172.77 -0.51 -7.75 16 17 C 0.51 6.36 7.70 -10.99 -0.08 6.28 16 18 O -0.54 -8.92 15.39 5.56 0.09 -8.84 16 19 C -0.14 -1.06 4.05 -27.89 -0.11 -1.17 16 20 C -0.10 -0.92 4.87 -26.73 -0.13 -1.05 16 21 C 0.06 0.44 4.74 37.16 0.18 0.62 16 22 O -0.31 -3.12 10.14 -19.43 -0.20 -3.32 16 23 C 0.13 1.22 6.69 -39.22 -0.26 0.96 16 24 C -0.21 -1.62 9.04 -39.43 -0.36 -1.97 16 25 C -0.08 -0.54 10.04 -39.60 -0.40 -0.94 16 26 C -0.16 -1.05 10.04 -39.56 -0.40 -1.45 16 27 C -0.08 -0.55 10.04 -39.61 -0.40 -0.95 16 28 C -0.15 -1.30 9.99 -39.44 -0.39 -1.69 16 29 C 0.12 1.66 5.72 -3.71 -0.02 1.64 16 30 H 0.26 7.48 8.31 -40.82 -0.34 7.14 16 31 H 0.38 10.11 6.86 -40.82 -0.28 9.83 16 32 H 0.02 0.42 8.14 -51.93 -0.42 0.00 16 33 H 0.02 0.40 8.14 -51.93 -0.42 -0.02 16 34 H 0.06 0.85 8.14 -51.93 -0.42 0.42 16 35 H 0.08 1.37 7.16 -51.93 -0.37 1.00 16 36 H 0.07 0.76 8.14 -51.93 -0.42 0.33 16 37 H 0.07 0.66 8.14 -51.93 -0.42 0.24 16 38 H 0.08 0.48 5.93 -51.93 -0.31 0.18 16 39 H 0.07 0.56 8.14 -51.93 -0.42 0.13 16 40 H 0.10 0.51 7.94 -51.93 -0.41 0.10 16 41 H 0.10 0.59 7.69 -51.92 -0.40 0.19 16 42 H 0.08 0.88 8.10 -51.93 -0.42 0.46 16 43 H 0.08 0.83 8.10 -51.93 -0.42 0.41 16 44 H 0.06 0.36 7.65 -51.93 -0.40 -0.03 16 45 H 0.06 0.39 7.67 -51.93 -0.40 -0.01 16 46 H 0.13 0.75 6.30 -52.49 -0.33 0.42 16 47 H 0.12 0.56 8.06 -52.49 -0.42 0.14 16 48 H 0.12 0.54 8.06 -52.49 -0.42 0.11 16 49 H 0.13 0.57 8.06 -52.49 -0.42 0.15 16 50 H 0.13 0.98 8.06 -52.49 -0.42 0.56 16 51 H 0.09 1.45 7.00 -51.93 -0.36 1.09 16 52 H 0.07 0.88 8.14 -51.93 -0.42 0.45 16 LS Contribution 415.59 15.07 6.26 6.26 Total: -1.00 -34.17 415.59 -10.88 -45.05 By element: Atomic # 1 Polarization: 14.35 SS G_CDS: -8.72 Total: 5.63 kcal Atomic # 6 Polarization: -5.09 SS G_CDS: -3.18 Total: -8.28 kcal Atomic # 7 Polarization: -53.90 SS G_CDS: -0.11 Total: -54.01 kcal Atomic # 8 Polarization: -12.04 SS G_CDS: -0.11 Total: -12.16 kcal Atomic # 14 Polarization: 22.52 SS G_CDS: -5.02 Total: 17.50 kcal Total LS contribution 6.26 Total: 6.26 kcal Total: -34.17 -10.88 -45.05 kcal The number of atoms in the molecule is 52 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. ZINC001566912574.mol2 52 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 -7.070 kcal (2) G-P(sol) polarization free energy of solvation -34.168 kcal (3) G-ENP(sol) elect.-nuc.-pol. free energy of system -41.238 kcal (4) G-CDS(sol) cavity-dispersion-solvent structure free energy -10.885 kcal (5) G-P-CDS(sol) = G-P(sol) + G-CDS(sol) = (2) + (4) -45.053 kcal (6) G-S(sol) free energy of system = (1) + (5) -52.123 kcal 1SCF WAS SPECIFIED, SO GEOMETRY OPTIMIZATION WAS NOT USED Total computer time = 1.19 seconds