Wall clock time and date at job start Tue Mar 31 2020 19:23:38 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 1.53005 * 1 3 3 C 1.52996 * 109.47162 * 2 1 4 4 H 1.09008 * 109.47787 * 54.97507 * 3 2 1 5 5 C 1.53085 * 109.48166 * 174.99755 * 3 2 1 6 6 C 1.53175 * 109.16446 * 177.60337 * 5 3 2 7 7 H 1.08998 * 109.54486 * 183.15469 * 6 5 3 8 8 C 1.50703 * 109.54322 * 62.97665 * 6 5 3 9 9 O 1.21274 * 119.99954 * 242.28997 * 8 6 5 10 10 N 1.34773 * 119.99593 * 62.29153 * 8 6 5 11 11 C 1.47178 * 136.00220 * 4.99403 * 10 8 6 12 12 C 1.53181 * 87.74147 * 153.41888 * 11 10 8 13 13 C 1.47170 * 135.99334 * 185.35485 * 10 8 6 14 14 C 1.52508 * 114.45250 * 272.10701 * 12 11 10 15 15 C 1.53209 * 109.35076 * 169.97756 * 14 12 11 16 16 C 1.53151 * 109.34193 * 58.89658 * 15 14 12 17 17 N 1.46884 * 109.12150 * 303.48483 * 16 15 14 18 18 C 1.36940 * 120.70099 * 235.42145 * 17 16 15 19 19 H 1.08004 * 119.99905 * 31.19421 * 18 17 16 20 20 C 1.38808 * 120.00376 * 211.19101 * 18 17 16 21 21 N 1.31613 * 119.99935 * 17.44697 * 20 18 17 22 22 Si 1.86801 * 120.00205 * 197.44731 * 20 18 17 23 23 H 1.48503 * 109.47026 * 89.99856 * 22 20 18 24 24 H 1.48491 * 109.47284 * 209.99882 * 22 20 18 25 25 H 1.48498 * 109.47263 * 330.00189 * 22 20 18 26 26 C 1.47140 * 118.60090 * 55.40343 * 17 16 15 27 27 C 1.53184 * 109.03609 * 303.02254 * 6 5 3 28 28 C 1.53083 * 109.16193 * 56.97917 * 27 6 5 29 29 O 1.42897 * 109.41821 * 302.38851 * 28 27 6 30 30 H 1.08997 * 109.47334 * 299.99773 * 1 2 3 31 31 H 1.08999 * 109.46821 * 60.00195 * 1 2 3 32 32 H 1.09002 * 109.47125 * 179.97438 * 1 2 3 33 33 H 1.09007 * 109.46934 * 239.99944 * 2 1 3 34 34 H 1.08996 * 109.46678 * 120.00560 * 2 1 3 35 35 H 1.09005 * 109.52038 * 57.70400 * 5 3 2 36 36 H 1.09000 * 109.52625 * 297.51145 * 5 3 2 37 37 H 1.09000 * 113.48817 * 268.11844 * 11 10 8 38 38 H 1.08998 * 113.48948 * 38.61917 * 11 10 8 39 39 H 1.08996 * 113.49714 * 321.37592 * 13 10 8 40 40 H 1.09001 * 113.48807 * 91.88661 * 13 10 8 41 41 H 1.08998 * 109.49062 * 289.94181 * 14 12 11 42 42 H 1.09004 * 109.48901 * 50.01531 * 14 12 11 43 43 H 1.09000 * 109.49414 * 178.85497 * 15 14 12 44 44 H 1.08997 * 109.49696 * 298.93399 * 15 14 12 45 45 H 1.09005 * 109.52612 * 63.37708 * 16 15 14 46 46 H 1.09001 * 109.52657 * 183.58381 * 16 15 14 47 47 H 0.97003 * 120.00218 * 179.97438 * 21 20 18 48 48 H 1.09003 * 109.64199 * 189.08111 * 26 17 16 49 49 H 1.09002 * 109.64425 * 68.46036 * 26 17 16 50 50 H 1.09000 * 109.51851 * 176.88809 * 27 6 5 51 51 H 1.08992 * 109.52127 * 297.07093 * 27 6 5 52 52 H 1.09007 * 109.47845 * 182.40562 * 28 27 6 53 53 H 1.08999 * 109.49469 * 62.38100 * 28 27 6 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 1.5301 0.0000 0.0000 3 6 2.0400 1.4425 0.0000 4 1 1.6051 1.9818 0.8416 5 6 3.5657 1.4446 0.1258 6 6 4.0733 2.8885 0.0649 7 1 5.1628 2.8937 0.0976 8 6 3.5300 3.6638 1.2374 9 8 2.8018 4.6153 1.0502 10 7 3.8535 3.2997 2.4941 11 6 4.7436 2.3035 3.1118 12 6 4.8332 3.2281 4.3298 13 6 3.4667 3.7195 3.8505 14 6 5.9380 4.2761 4.2469 15 6 5.7683 5.2841 5.3882 16 6 5.8280 4.5468 6.7292 17 7 4.8005 3.4972 6.7474 18 6 3.8652 3.4517 7.7466 19 1 3.5293 4.3656 8.2139 20 6 3.3488 2.2310 8.1589 21 7 3.9773 1.1148 7.8568 22 14 1.7618 2.1724 9.1425 23 1 0.6077 2.0657 8.2141 24 1 1.7819 0.9932 10.0448 25 1 1.6341 3.4118 9.9504 26 6 4.7971 2.4961 5.6692 27 6 3.5968 3.5308 -1.2416 28 6 2.0700 3.4481 -1.3145 29 8 1.6632 2.0815 -1.2215 30 1 -0.3634 0.5138 0.8900 31 1 -0.3633 0.5138 -0.8900 32 1 -0.3633 -1.0277 -0.0005 33 1 1.8934 -0.5139 -0.8900 34 1 1.8933 -0.5139 0.8899 35 1 3.9995 0.8711 -0.6934 36 1 3.8534 0.9972 1.0773 37 1 4.2524 1.3535 3.3226 38 1 5.6906 2.1818 2.5861 39 1 3.3328 4.7966 3.9504 40 1 2.6322 3.1504 4.2601 41 1 6.9090 3.7885 4.3338 42 1 5.8756 4.7955 3.2906 43 1 6.5687 6.0226 5.3433 44 1 4.8050 5.7848 5.2910 45 1 6.8123 4.0953 6.8533 46 1 5.6441 5.2510 7.5407 47 1 3.6167 0.2617 8.1451 48 1 3.8917 1.8924 5.7325 49 1 5.6748 1.8561 5.7606 50 1 3.9068 4.5755 -1.2680 51 1 4.0313 2.9996 -2.0883 52 1 1.7282 3.8654 -2.2618 53 1 1.6353 4.0137 -0.4904 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 ZINC000982106450.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 19:23:38 Heat of formation + Delta-G solvation = -39.227594 kcal Electronic energy + Delta-G solvation = -31594.866316 eV Core-core repulsion = 27660.659072 eV Total energy + Delta-G solvation = -3934.207243 eV No. of doubly occupied orbitals = 65 Molecular weight (most abundant/longest-lived isotopes) = 336.220 amu Computer time = 1.15 seconds Orbital eigenvalues (eV) -41.00423 -39.72628 -37.76310 -35.88575 -34.06170 -33.79697 -32.87222 -30.57127 -30.09482 -29.69746 -26.77723 -25.78354 -25.39761 -25.04954 -23.82129 -22.36256 -21.80987 -21.27173 -20.54036 -18.57374 -17.84271 -16.82050 -16.76921 -16.51295 -16.16813 -15.75528 -15.37110 -14.78319 -14.71227 -14.14522 -14.07037 -13.83152 -13.79268 -13.65091 -13.51285 -13.20899 -12.94846 -12.84249 -12.55696 -12.43857 -12.09816 -11.94288 -11.83016 -11.76459 -11.59401 -11.31891 -11.26946 -11.06746 -11.04253 -10.81631 -10.73290 -10.52781 -10.42419 -10.28400 -10.12864 -9.95777 -9.83061 -9.62893 -9.46548 -9.15690 -8.54721 -8.43394 -6.69883 -5.87355 -3.31117 2.71141 3.04469 3.33650 3.41708 3.42549 3.72401 4.35831 4.42128 4.43206 4.64690 4.66054 4.72375 4.91863 5.02838 5.11664 5.14708 5.24825 5.31916 5.34413 5.36876 5.45278 5.50681 5.51488 5.58460 5.61481 5.70370 5.72047 5.74288 5.78467 5.82430 5.85783 5.85899 5.92889 5.99098 6.01775 6.04624 6.09984 6.13045 6.21277 6.22636 6.34700 6.48337 6.56876 6.70213 6.81001 6.94790 7.14670 7.21472 7.40542 7.75883 7.97365 8.29520 8.38334 9.13516 9.76004 10.35501 11.21536 Molecular weight = 336.22amu Principal moments of inertia in cm(-1) A = 0.012563 B = 0.003656 C = 0.003099 Principal moments of inertia in units of 10**(-40)*gram-cm**2 A = 2228.175544 B = 7656.825122 C = 9033.521731 Net atomic charges, atomic populations, and dipole contributions calculated with CM2 Atom NO. Type Charge No. of electrons 1 C -0.150 4.150 2 C -0.114 4.114 3 C 0.090 3.910 4 H 0.057 0.943 5 C -0.140 4.140 6 C -0.106 4.106 7 H 0.097 0.903 8 C 0.541 3.459 9 O -0.547 6.547 10 N -0.641 5.641 11 C 0.106 3.894 12 C -0.111 4.111 13 C 0.125 3.875 14 C -0.079 4.079 15 C -0.134 4.134 16 C 0.145 3.855 17 N -0.588 5.588 18 C -0.255 4.255 19 H 0.064 0.936 20 C 0.009 3.991 21 N -0.900 5.900 22 Si 0.898 3.102 23 H -0.287 1.287 24 H -0.291 1.291 25 H -0.278 1.278 26 C 0.196 3.804 27 C -0.132 4.132 28 C 0.050 3.950 29 O -0.380 6.380 30 H 0.052 0.948 31 H 0.061 0.939 32 H 0.053 0.947 33 H 0.069 0.931 34 H 0.076 0.924 35 H 0.081 0.919 36 H 0.080 0.920 37 H 0.087 0.913 38 H 0.072 0.928 39 H 0.071 0.929 40 H 0.085 0.915 41 H 0.060 0.940 42 H 0.047 0.953 43 H 0.051 0.949 44 H 0.058 0.942 45 H 0.018 0.982 46 H 0.053 0.947 47 H 0.254 0.746 48 H 0.081 0.919 49 H 0.028 0.972 50 H 0.078 0.922 51 H 0.074 0.926 52 H 0.089 0.911 53 H 0.077 0.923 For the charges calculated by CM2: Dipole moment (debyes) X Y Z Total from point charges 1.669 -0.511 -16.594 16.686 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 -0.207 4.207 2 C -0.152 4.152 3 C 0.032 3.968 4 H 0.075 0.925 5 C -0.178 4.178 6 C -0.127 4.127 7 H 0.115 0.885 8 C 0.331 3.669 9 O -0.426 6.426 10 N -0.375 5.375 11 C -0.018 4.018 12 C -0.114 4.114 13 C 0.003 3.997 14 C -0.117 4.117 15 C -0.173 4.173 16 C 0.019 3.981 17 N -0.311 5.311 18 C -0.385 4.385 19 H 0.082 0.918 20 C -0.190 4.190 21 N -0.544 5.544 22 Si 0.728 3.272 23 H -0.214 1.214 24 H -0.217 1.217 25 H -0.203 1.203 26 C 0.069 3.931 27 C -0.170 4.170 28 C -0.027 4.027 29 O -0.299 6.299 30 H 0.072 0.928 31 H 0.080 0.920 32 H 0.072 0.928 33 H 0.088 0.912 34 H 0.095 0.905 35 H 0.100 0.900 36 H 0.098 0.902 37 H 0.105 0.895 38 H 0.090 0.910 39 H 0.090 0.910 40 H 0.103 0.897 41 H 0.079 0.921 42 H 0.066 0.934 43 H 0.070 0.930 44 H 0.076 0.924 45 H 0.036 0.964 46 H 0.072 0.928 47 H 0.064 0.936 48 H 0.099 0.901 49 H 0.046 0.954 50 H 0.097 0.903 51 H 0.093 0.907 52 H 0.107 0.893 53 H 0.095 0.905 Dipole moment (debyes) X Y Z Total from point charges 1.075 -0.198 -16.975 17.010 hybrid contribution -0.539 -0.036 0.710 0.892 sum 0.536 -0.234 -16.265 16.275 Atomic orbital electron populations 1.21709 0.95215 1.01427 1.02357 1.21532 0.96871 0.94129 1.02645 1.22112 0.92927 0.94214 0.87575 0.92545 1.22212 0.97065 0.94823 1.03726 1.21331 1.01886 0.95786 0.93741 0.88536 1.20081 0.80350 0.84206 0.82285 1.90624 1.38421 1.29125 1.84428 1.49859 1.45055 1.37982 1.04591 1.23188 0.93300 0.93423 0.91863 1.22602 0.94835 0.96649 0.97310 1.22974 0.97897 1.01202 0.77611 1.21011 0.96949 0.95829 0.97903 1.22021 1.00747 0.97406 0.97148 1.20897 0.91919 0.91282 0.94009 1.43965 1.31747 1.30407 1.24942 1.19139 1.14831 0.91888 1.12629 0.91791 1.25076 0.99406 0.95984 0.98564 1.70023 1.37684 0.97230 1.49442 0.86362 0.83905 0.77254 0.79709 1.21374 1.21730 1.20343 1.20524 1.01323 0.89750 0.81468 1.21955 0.97790 1.01713 0.95529 1.22806 0.93609 0.83058 1.03183 1.87867 1.78779 1.25094 1.38165 0.92849 0.92025 0.92784 0.91178 0.90534 0.90006 0.90161 0.89479 0.90994 0.91015 0.89661 0.92112 0.93401 0.92996 0.92361 0.96381 0.92801 0.93584 0.90062 0.95422 0.90306 0.90714 0.89328 0.90468 Number of geometries 1 Number of calculations of the screened coulomb radii 1 The total number of SCF iterations 18. 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 -0.15 -1.56 9.81 37.16 0.36 -1.20 16 2 C -0.11 -1.19 5.64 -26.73 -0.15 -1.34 16 3 C 0.09 1.09 2.42 -26.69 -0.06 1.03 16 4 H 0.06 0.82 7.38 -51.92 -0.38 0.44 16 5 C -0.14 -1.50 4.85 -26.60 -0.13 -1.63 16 6 C -0.11 -1.24 2.88 -91.58 -0.26 -1.51 16 7 H 0.10 0.99 8.14 -51.93 -0.42 0.56 16 8 C 0.54 8.27 6.07 -10.99 -0.07 8.20 16 9 O -0.55 -10.09 14.57 5.56 0.08 -10.01 16 10 N -0.64 -9.71 3.39 -184.97 -0.63 -10.34 16 11 C 0.11 1.45 6.28 -8.05 -0.05 1.40 16 12 C -0.11 -1.85 0.95 -154.88 -0.15 -1.99 16 13 C 0.12 2.15 7.65 -8.19 -0.06 2.09 16 14 C -0.08 -1.23 5.10 -26.88 -0.14 -1.37 16 15 C -0.13 -2.22 6.02 -26.55 -0.16 -2.38 16 16 C 0.15 2.87 6.45 -3.75 -0.02 2.84 16 17 N -0.59 -13.62 2.98 -172.51 -0.51 -14.13 16 18 C -0.26 -6.62 9.54 -15.06 -0.14 -6.77 16 19 H 0.06 1.66 7.89 -52.48 -0.41 1.25 16 20 C 0.01 0.24 4.88 -17.43 -0.09 0.15 16 21 N -0.90 -24.58 11.53 55.49 0.64 -23.94 16 22 Si 0.90 20.91 29.59 -169.99 -5.03 15.88 16 23 H -0.29 -6.69 7.11 56.52 0.40 -6.29 16 24 H -0.29 -6.87 7.11 56.52 0.40 -6.46 16 25 H -0.28 -6.41 7.11 56.52 0.40 -6.00 16 26 C 0.20 4.11 4.45 -3.86 -0.02 4.09 16 27 C -0.13 -1.47 5.28 -26.59 -0.14 -1.61 16 28 C 0.05 0.62 6.55 37.20 0.24 0.86 16 29 O -0.38 -4.98 9.95 -35.23 -0.35 -5.33 16 30 H 0.05 0.59 8.14 -51.93 -0.42 0.17 16 31 H 0.06 0.68 7.82 -51.93 -0.41 0.27 16 32 H 0.05 0.49 8.14 -51.93 -0.42 0.06 16 33 H 0.07 0.68 8.14 -51.92 -0.42 0.25 16 34 H 0.08 0.73 8.14 -51.93 -0.42 0.31 16 35 H 0.08 0.77 8.14 -51.93 -0.42 0.34 16 36 H 0.08 0.83 6.63 -51.93 -0.34 0.49 16 37 H 0.09 1.15 7.98 -51.93 -0.41 0.74 16 38 H 0.07 0.84 8.12 -51.93 -0.42 0.41 16 39 H 0.07 1.32 7.46 -51.93 -0.39 0.93 16 40 H 0.09 1.56 7.96 -51.93 -0.41 1.15 16 41 H 0.06 0.90 8.14 -51.93 -0.42 0.48 16 42 H 0.05 0.72 7.96 -51.93 -0.41 0.31 16 43 H 0.05 0.75 8.14 -51.93 -0.42 0.32 16 44 H 0.06 1.03 7.47 -51.93 -0.39 0.64 16 45 H 0.02 0.36 8.14 -51.93 -0.42 -0.06 16 46 H 0.05 1.06 7.93 -51.93 -0.41 0.65 16 47 H 0.25 6.76 8.31 -40.82 -0.34 6.42 16 48 H 0.08 1.91 6.30 -51.93 -0.33 1.58 16 49 H 0.03 0.62 8.14 -51.93 -0.42 0.20 16 50 H 0.08 0.89 8.05 -51.93 -0.42 0.47 16 51 H 0.07 0.71 8.14 -51.93 -0.42 0.28 16 52 H 0.09 0.94 8.14 -51.93 -0.42 0.51 16 53 H 0.08 1.16 5.75 -51.93 -0.30 0.87 16 LS Contribution 398.88 15.07 6.01 6.01 Total: -1.00 -29.22 398.88 -10.47 -39.70 By element: Atomic # 1 Polarization: 10.94 SS G_CDS: -9.65 Total: 1.29 kcal Atomic # 6 Polarization: 1.92 SS G_CDS: -1.04 Total: 0.88 kcal Atomic # 7 Polarization: -47.91 SS G_CDS: -0.50 Total: -48.41 kcal Atomic # 8 Polarization: -15.08 SS G_CDS: -0.27 Total: -15.35 kcal Atomic # 14 Polarization: 20.91 SS G_CDS: -5.03 Total: 15.88 kcal Total LS contribution 6.01 Total: 6.01 kcal Total: -29.22 -10.47 -39.70 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. ZINC000982106450.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 0.468 kcal (2) G-P(sol) polarization free energy of solvation -29.221 kcal (3) G-ENP(sol) elect.-nuc.-pol. free energy of system -28.753 kcal (4) G-CDS(sol) cavity-dispersion-solvent structure free energy -10.475 kcal (5) G-P-CDS(sol) = G-P(sol) + G-CDS(sol) = (2) + (4) -39.695 kcal (6) G-S(sol) free energy of system = (1) + (5) -39.228 kcal 1SCF WAS SPECIFIED, SO GEOMETRY OPTIMIZATION WAS NOT USED Total computer time = 1.15 seconds