Wall clock time and date at job start Wed Apr 1 2020 01:55:08 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 1.50701 * 1 3 3 C 1.38234 * 120.00243 * 2 1 4 4 C 1.38234 * 120.00240 * 180.02562 * 3 2 1 5 5 C 1.38233 * 120.00037 * 0.26327 * 4 3 2 6 6 C 1.38238 * 119.99752 * 359.47832 * 5 4 3 7 7 C 1.50698 * 120.00194 * 180.23536 * 6 5 4 8 8 C 1.38234 * 120.00005 * 0.52168 * 6 5 4 9 9 C 1.50706 * 120.00207 * 179.72183 * 8 6 5 10 10 C 1.50701 * 109.46813 * 270.01852 * 9 8 6 11 11 O 1.21282 * 119.99907 * 359.97438 * 10 9 8 12 12 N 1.34776 * 119.99886 * 179.97438 * 10 9 8 13 13 C 1.46798 * 119.57967 * 359.97438 * 12 10 9 14 14 C 1.53457 * 107.59393 * 127.94400 * 13 12 10 15 15 C 1.52732 * 108.44168 * 58.08354 * 14 13 12 16 16 C 1.53008 * 110.80347 * 296.23318 * 15 14 13 17 17 H 1.09001 * 111.38628 * 290.26816 * 16 15 14 18 18 C 1.45118 * 119.57450 * 179.73027 * 12 10 9 19 19 H 1.09000 * 109.97544 * 348.06882 * 18 12 10 20 20 C 1.54422 * 111.60768 * 111.35271 * 18 12 10 21 21 C 1.54564 * 102.45034 * 156.57690 * 20 18 12 22 22 N 1.46008 * 107.33330 * 338.32161 * 21 20 18 23 23 C 1.36934 * 125.65485 * 177.29713 * 22 21 20 24 24 H 1.08000 * 120.00452 * 180.24296 * 23 22 21 25 25 C 1.38818 * 120.00001 * 0.24778 * 23 22 21 26 26 N 1.31616 * 119.99567 * 359.97438 * 25 23 22 27 27 Si 1.86801 * 120.00036 * 179.97438 * 25 23 22 28 28 H 1.48498 * 109.47302 * 0.02562 * 27 25 23 29 29 H 1.48505 * 109.46970 * 119.99913 * 27 25 23 30 30 H 1.48500 * 109.46889 * 239.99768 * 27 25 23 31 31 H 1.08998 * 109.46845 * 89.99854 * 1 2 3 32 32 H 1.08996 * 109.47280 * 210.00015 * 1 2 3 33 33 H 1.08999 * 109.46887 * 329.99909 * 1 2 3 34 34 H 1.07999 * 119.99751 * 359.97438 * 3 2 1 35 35 H 1.08002 * 119.99744 * 179.97438 * 4 3 2 36 36 H 1.07998 * 120.00391 * 179.72199 * 5 4 3 37 37 H 1.09003 * 109.47132 * 270.28479 * 7 6 5 38 38 H 1.09007 * 109.46985 * 30.28364 * 7 6 5 39 39 H 1.08993 * 109.47251 * 150.28233 * 7 6 5 40 40 H 1.09000 * 109.46849 * 30.01510 * 9 8 6 41 41 H 1.08993 * 109.47102 * 150.01806 * 9 8 6 42 42 H 1.09004 * 109.83630 * 247.47111 * 13 12 10 43 43 H 1.09002 * 109.83146 * 8.41783 * 13 12 10 44 44 H 1.09007 * 109.63981 * 177.76683 * 14 13 12 45 45 H 1.08997 * 109.64349 * 298.18506 * 14 13 12 46 46 H 1.08999 * 109.21518 * 56.57121 * 15 14 13 47 47 H 1.09002 * 109.21136 * 175.93583 * 15 14 13 48 48 H 1.09000 * 110.81510 * 274.82203 * 20 18 12 49 49 H 1.09005 * 110.80844 * 38.34237 * 20 18 12 50 50 H 1.09000 * 109.88406 * 97.73810 * 21 20 18 51 51 H 1.09000 * 109.88994 * 218.75836 * 21 20 18 52 52 H 0.97004 * 119.99868 * 180.02562 * 26 25 23 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 1.5070 0.0000 0.0000 3 6 2.1982 1.1971 0.0000 4 6 3.5806 1.1971 -0.0005 5 6 4.2717 0.0000 -0.0066 6 6 3.5806 -1.1972 -0.0012 7 6 4.3340 -2.5023 -0.0024 8 6 2.1982 -1.1972 -0.0006 9 6 1.4446 -2.5023 -0.0011 10 6 1.1933 -2.9367 -1.4221 11 8 1.5870 -2.2535 -2.3436 12 7 0.5312 -4.0843 -1.6688 13 6 0.0594 -4.9044 -0.5464 14 6 -1.4330 -5.1827 -0.7704 15 6 -1.5967 -5.8854 -2.1165 16 6 -1.1548 -4.9734 -3.2629 17 1 -1.8472 -4.1428 -3.3995 18 6 0.2891 -4.4909 -3.0407 19 1 0.5148 -3.6675 -3.7184 20 6 1.1073 -5.7460 -3.4146 21 6 0.2926 -6.3376 -4.5874 22 7 -1.0664 -5.8147 -4.4805 23 6 -2.0867 -6.0577 -5.3608 24 1 -3.0595 -5.6191 -5.1945 25 6 -1.8707 -6.8681 -6.4671 26 7 -0.6851 -7.4023 -6.6700 27 14 -3.2628 -7.2002 -7.6676 28 1 -4.4854 -6.4878 -7.2172 29 1 -2.8779 -6.7167 -9.0179 30 1 -3.5315 -8.6597 -7.7224 31 1 -0.3633 0.0000 -1.0277 32 1 -0.3633 -0.8899 0.5138 33 1 -0.3633 0.8900 0.5138 34 1 1.6582 2.1324 -0.0004 35 1 4.1205 2.1325 -0.0010 36 1 5.3517 -0.0001 -0.0115 37 1 4.5152 -2.8162 -1.0304 38 1 5.2867 -2.3723 0.5112 39 1 3.7452 -3.2622 0.5112 40 1 2.0338 -3.2621 0.5123 41 1 0.4923 -2.3721 0.5129 42 1 0.6107 -5.8443 -0.5176 43 1 0.1985 -4.3644 0.3902 44 1 -1.8096 -5.8245 0.0262 45 1 -1.9844 -4.2425 -0.7748 46 1 -0.9902 -6.7910 -2.1246 47 1 -2.6439 -6.1539 -2.2560 48 1 2.1108 -5.4716 -3.7397 49 1 1.1472 -6.4453 -2.5794 50 1 0.7333 -6.0318 -5.5363 51 1 0.2795 -7.4253 -4.5184 52 1 -0.5341 -7.9682 -7.4432 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 ZINC001049502856.mol2 52 1SCF WAS SPECIFIED, SO GEOMETRY OPTIMIZATION WAS NOT USED SCF FIELD WAS ACHIEVED Wall clock time and date at job start Wed Apr 1 2020 01:55:08 Heat of formation + Delta-G solvation = 13.686708 kcal Electronic energy + Delta-G solvation = -31176.146567 eV Core-core repulsion = 27333.775249 eV Total energy + Delta-G solvation = -3842.371317 eV No. of doubly occupied orbitals = 65 Molecular weight (most abundant/longest-lived isotopes) = 342.205 amu Computer time = 1.27 seconds Orbital eigenvalues (eV) -40.66366 -39.57923 -37.81744 -35.29402 -33.67653 -33.46035 -32.37439 -32.18432 -29.48851 -28.73244 -28.14755 -26.73777 -26.67909 -24.50472 -24.27528 -22.07195 -21.52556 -20.77669 -20.11711 -19.67218 -18.07473 -17.21362 -16.88767 -16.36616 -16.25721 -15.48471 -14.79041 -14.77088 -14.63165 -14.24916 -14.15445 -13.83905 -13.47231 -13.45766 -13.35365 -13.02778 -12.99524 -12.86490 -12.77087 -12.56986 -12.33611 -12.06446 -11.93978 -11.67382 -11.55402 -11.37742 -11.06511 -10.99038 -10.96237 -10.87853 -10.79458 -10.65047 -10.46308 -10.05670 -10.04866 -9.66102 -9.60989 -9.51151 -8.61640 -8.61213 -8.57304 -8.24236 -6.85510 -5.71065 -3.05444 1.29347 1.34098 2.81658 3.19104 3.39899 3.45509 3.47819 3.71167 4.48172 4.51332 4.68308 4.70765 4.80391 4.86704 4.93872 4.98423 5.13191 5.14832 5.26875 5.28414 5.31538 5.40431 5.48778 5.53048 5.54399 5.56006 5.60027 5.65608 5.66910 5.70333 5.75749 5.79750 5.88238 5.99900 6.08173 6.10962 6.14513 6.22525 6.30958 6.37002 6.43021 6.47904 6.52000 6.60587 6.61480 6.75011 6.97453 7.00774 7.07600 7.56316 7.61739 7.66974 7.83823 8.25228 8.42491 9.22307 9.80964 10.46471 11.39753 Molecular weight = 342.20amu Principal moments of inertia in cm(-1) A = 0.018812 B = 0.002731 C = 0.002715 Principal moments of inertia in units of 10**(-40)*gram-cm**2 A = 1488.052220 B =10248.375391 C =10311.048903 Net atomic charges, atomic populations, and dipole contributions calculated with CM2 Atom NO. Type Charge No. of electrons 1 C -0.119 4.119 2 C -0.067 4.067 3 C -0.128 4.128 4 C -0.115 4.115 5 C -0.128 4.128 6 C -0.067 4.067 7 C -0.118 4.118 8 C -0.064 4.064 9 C -0.109 4.109 10 C 0.513 3.487 11 O -0.532 6.532 12 N -0.595 5.595 13 C 0.105 3.895 14 C -0.133 4.133 15 C -0.129 4.129 16 C 0.155 3.845 17 H 0.058 0.942 18 C 0.132 3.868 19 H 0.100 0.900 20 C -0.151 4.151 21 C 0.181 3.819 22 N -0.597 5.597 23 C -0.226 4.226 24 H 0.078 0.922 25 C -0.007 4.007 26 N -0.920 5.920 27 Si 0.911 3.089 28 H -0.280 1.280 29 H -0.291 1.291 30 H -0.291 1.291 31 H 0.074 0.926 32 H 0.066 0.934 33 H 0.065 0.935 34 H 0.119 0.881 35 H 0.119 0.881 36 H 0.119 0.881 37 H 0.074 0.926 38 H 0.065 0.935 39 H 0.066 0.934 40 H 0.102 0.898 41 H 0.102 0.898 42 H 0.070 0.930 43 H 0.079 0.921 44 H 0.068 0.932 45 H 0.063 0.937 46 H 0.063 0.937 47 H 0.059 0.941 48 H 0.059 0.941 49 H 0.058 0.942 50 H 0.049 0.951 51 H 0.040 0.960 52 H 0.252 0.748 For the charges calculated by CM2: Dipole moment (debyes) X Y Z Total from point charges 6.490 11.019 19.847 23.610 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 -0.175 4.175 2 C -0.067 4.067 3 C -0.146 4.146 4 C -0.133 4.133 5 C -0.146 4.146 6 C -0.067 4.067 7 C -0.175 4.175 8 C -0.064 4.064 9 C -0.148 4.148 10 C 0.300 3.700 11 O -0.408 6.408 12 N -0.327 5.327 13 C -0.018 4.018 14 C -0.172 4.172 15 C -0.169 4.169 16 C 0.047 3.953 17 H 0.076 0.924 18 C 0.028 3.972 19 H 0.118 0.882 20 C -0.190 4.190 21 C 0.056 3.944 22 N -0.321 5.321 23 C -0.355 4.355 24 H 0.096 0.904 25 C -0.204 4.204 26 N -0.568 5.568 27 Si 0.742 3.258 28 H -0.205 1.205 29 H -0.218 1.218 30 H -0.218 1.218 31 H 0.093 0.907 32 H 0.085 0.915 33 H 0.084 0.916 34 H 0.137 0.863 35 H 0.137 0.863 36 H 0.137 0.863 37 H 0.092 0.908 38 H 0.084 0.916 39 H 0.085 0.915 40 H 0.120 0.880 41 H 0.120 0.880 42 H 0.088 0.912 43 H 0.098 0.902 44 H 0.086 0.914 45 H 0.082 0.918 46 H 0.082 0.918 47 H 0.078 0.922 48 H 0.078 0.922 49 H 0.077 0.923 50 H 0.068 0.932 51 H 0.058 0.942 52 H 0.062 0.938 Dipole moment (debyes) X Y Z Total from point charges 6.660 11.231 19.099 23.136 hybrid contribution -0.700 -0.353 -0.720 1.065 sum 5.960 10.878 18.379 22.173 Atomic orbital electron populations 1.20871 0.91413 1.02406 1.02815 1.19676 0.95868 0.92555 0.98568 1.20920 0.94251 0.97211 1.02196 1.21051 0.94289 0.97794 1.00166 1.20918 0.99502 0.91955 1.02198 1.19674 0.92968 0.95450 0.98598 1.20870 0.99536 0.94288 1.02794 1.18969 0.92755 0.93221 1.01502 1.20823 1.01987 0.96240 0.95766 1.20419 0.78060 0.80626 0.90853 1.90714 1.50494 1.53430 1.46147 1.47637 1.55755 1.22137 1.07169 1.21851 0.95641 0.95649 0.88631 1.21925 0.95015 1.01188 0.99065 1.22103 1.01987 0.99631 0.93209 1.21301 0.93190 0.92949 0.87883 0.92376 1.21657 0.96603 0.97774 0.81199 0.88180 1.23117 0.99031 0.96582 1.00301 1.20966 0.83330 0.96696 0.93396 1.44470 1.08575 1.55059 1.24000 1.19075 0.90194 1.24849 1.01353 0.90416 1.24805 0.97019 0.99949 0.98592 1.69978 1.20437 1.36721 1.29629 0.86052 0.81069 0.77580 0.81100 1.20524 1.21764 1.21797 0.90736 0.91493 0.91613 0.86305 0.86325 0.86309 0.90752 0.91620 0.91504 0.88026 0.87963 0.91222 0.90239 0.91351 0.91840 0.91841 0.92178 0.92177 0.92330 0.93245 0.94190 0.93800 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 -0.12 -1.19 9.60 36.01 0.35 -0.85 16 2 C -0.07 -0.79 5.88 -104.62 -0.62 -1.41 16 3 C -0.13 -1.41 9.70 -39.58 -0.38 -1.79 16 4 C -0.11 -1.21 10.05 -39.58 -0.40 -1.61 16 5 C -0.13 -1.40 9.70 -39.58 -0.38 -1.79 16 6 C -0.07 -0.79 5.88 -104.62 -0.62 -1.41 16 7 C -0.12 -1.18 9.60 36.00 0.35 -0.84 16 8 C -0.06 -0.79 4.37 -104.62 -0.46 -1.25 16 9 C -0.11 -1.19 3.33 -29.03 -0.10 -1.29 16 10 C 0.51 7.73 7.65 -10.99 -0.08 7.64 16 11 O -0.53 -10.30 15.36 5.56 0.09 -10.22 16 12 N -0.59 -8.83 2.74 -165.24 -0.45 -9.28 16 13 C 0.11 1.19 6.05 -3.64 -0.02 1.17 16 14 C -0.13 -1.63 6.11 -26.63 -0.16 -1.79 16 15 C -0.13 -2.19 5.10 -26.86 -0.14 -2.33 16 16 C 0.16 3.13 3.58 -66.51 -0.24 2.89 16 17 H 0.06 1.21 8.14 -51.93 -0.42 0.79 16 18 C 0.13 2.47 3.10 -67.48 -0.21 2.26 16 19 H 0.10 2.17 6.96 -51.93 -0.36 1.81 16 20 C -0.15 -2.91 6.08 -25.16 -0.15 -3.07 16 21 C 0.18 4.41 5.15 -3.49 -0.02 4.39 16 22 N -0.60 -14.89 2.88 -163.24 -0.47 -15.36 16 23 C -0.23 -6.22 10.29 -15.06 -0.15 -6.37 16 24 H 0.08 2.07 7.83 -52.49 -0.41 1.66 16 25 C -0.01 -0.21 5.48 -17.43 -0.10 -0.30 16 26 N -0.92 -26.97 10.31 55.49 0.57 -26.40 16 27 Si 0.91 22.11 29.55 -169.99 -5.02 17.09 16 28 H -0.28 -6.58 7.11 56.52 0.40 -6.18 16 29 H -0.29 -7.14 7.11 56.52 0.40 -6.74 16 30 H -0.29 -7.09 7.11 56.52 0.40 -6.69 16 31 H 0.07 0.86 8.14 -51.93 -0.42 0.43 16 32 H 0.07 0.59 5.95 -51.93 -0.31 0.28 16 33 H 0.06 0.53 8.09 -51.93 -0.42 0.11 16 34 H 0.12 1.06 8.06 -52.49 -0.42 0.64 16 35 H 0.12 0.96 8.06 -52.49 -0.42 0.54 16 36 H 0.12 1.06 8.06 -52.49 -0.42 0.63 16 37 H 0.07 0.85 8.14 -51.93 -0.42 0.42 16 38 H 0.06 0.53 8.09 -51.93 -0.42 0.11 16 39 H 0.07 0.58 5.95 -51.93 -0.31 0.28 16 40 H 0.10 0.90 5.74 -51.93 -0.30 0.61 16 41 H 0.10 0.91 5.42 -51.93 -0.28 0.63 16 42 H 0.07 0.77 7.54 -51.93 -0.39 0.38 16 43 H 0.08 0.65 5.82 -51.93 -0.30 0.35 16 44 H 0.07 0.69 8.14 -51.93 -0.42 0.27 16 45 H 0.06 0.77 8.14 -51.93 -0.42 0.35 16 46 H 0.06 1.16 7.13 -51.93 -0.37 0.79 16 47 H 0.06 1.08 8.14 -51.93 -0.42 0.66 16 48 H 0.06 1.13 8.14 -51.93 -0.42 0.71 16 49 H 0.06 1.03 6.82 -51.93 -0.35 0.68 16 50 H 0.05 1.36 7.28 -51.93 -0.38 0.98 16 51 H 0.04 1.06 7.58 -51.93 -0.39 0.67 16 52 H 0.25 7.18 8.31 -40.82 -0.34 6.84 16 LS Contribution 394.54 15.07 5.95 5.95 Total: -1.00 -32.73 394.54 -11.24 -43.97 By element: Atomic # 1 Polarization: 10.35 SS G_CDS: -8.36 Total: 1.99 kcal Atomic # 6 Polarization: -4.21 SS G_CDS: -3.53 Total: -7.74 kcal Atomic # 7 Polarization: -50.69 SS G_CDS: -0.35 Total: -51.04 kcal Atomic # 8 Polarization: -10.30 SS G_CDS: 0.09 Total: -10.22 kcal Atomic # 14 Polarization: 22.11 SS G_CDS: -5.02 Total: 17.09 kcal Total LS contribution 5.95 Total: 5.95 kcal Total: -32.73 -11.24 -43.97 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. ZINC001049502856.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 57.658 kcal (2) G-P(sol) polarization free energy of solvation -32.732 kcal (3) G-ENP(sol) elect.-nuc.-pol. free energy of system 24.926 kcal (4) G-CDS(sol) cavity-dispersion-solvent structure free energy -11.239 kcal (5) G-P-CDS(sol) = G-P(sol) + G-CDS(sol) = (2) + (4) -43.971 kcal (6) G-S(sol) free energy of system = (1) + (5) 13.687 kcal 1SCF WAS SPECIFIED, SO GEOMETRY OPTIMIZATION WAS NOT USED Total computer time = 1.27 seconds