Wall clock time and date at job start Sat Apr 11 2020 06:08:48 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 1.53003 * 1 3 3 O 1.42897 * 112.84380 * 2 1 4 4 C 1.42905 * 114.00262 * 50.33487 * 3 2 1 5 5 C 1.50697 * 109.47007 * 179.97438 * 4 3 2 6 6 O 1.21283 * 120.00521 * 359.72812 * 5 4 3 7 7 N 1.34784 * 119.99774 * 179.97438 * 5 4 3 8 8 C 1.46499 * 119.99971 * 359.72768 * 7 5 4 9 9 C 1.50703 * 109.47219 * 89.99688 * 8 7 5 10 10 H 1.07996 * 119.99587 * 359.97438 * 9 8 7 11 11 C 1.37875 * 120.00012 * 180.02562 * 9 8 7 12 12 N 1.31514 * 120.00204 * 0.02562 * 11 9 8 13 13 Si 1.86802 * 119.99711 * 180.02562 * 11 9 8 14 14 H 1.48494 * 109.47341 * 359.97438 * 13 11 9 15 15 H 1.48497 * 109.46996 * 119.99906 * 13 11 9 16 16 H 1.48509 * 109.46812 * 239.99713 * 13 11 9 17 17 C 1.46499 * 119.99893 * 179.72962 * 7 5 4 18 18 C 1.52996 * 109.47198 * 90.00083 * 17 7 5 19 19 N 1.46902 * 109.46980 * 179.97438 * 18 17 7 20 20 C 1.47015 * 111.00009 * 293.63325 * 19 18 17 21 21 C 1.53100 * 109.25969 * 177.60615 * 20 19 18 22 22 O 1.43020 * 109.25371 * 56.84894 * 21 20 19 23 23 C 1.43015 * 113.74045 * 301.33009 * 22 21 20 24 24 C 1.47013 * 110.99990 * 170.00210 * 19 18 17 25 25 C 1.53776 * 113.61582 * 131.19445 * 2 1 3 26 26 C 1.53960 * 87.01693 * 89.23434 * 25 2 1 27 27 C 1.53773 * 113.61479 * 228.80823 * 2 1 3 28 28 H 1.08992 * 109.47325 * 69.66845 * 1 2 3 29 29 H 1.09006 * 109.46271 * 189.66518 * 1 2 3 30 30 H 1.08994 * 109.47219 * 309.65826 * 1 2 3 31 31 H 1.09001 * 109.46781 * 60.00188 * 4 3 2 32 32 H 1.08993 * 109.47173 * 299.99979 * 4 3 2 33 33 H 1.08998 * 109.47416 * 209.99869 * 8 7 5 34 34 H 1.09008 * 109.47058 * 330.00468 * 8 7 5 35 35 H 0.97000 * 120.00290 * 180.02562 * 12 11 9 36 36 H 1.08997 * 109.46865 * 210.00034 * 17 7 5 37 37 H 1.08998 * 109.47058 * 329.99547 * 17 7 5 38 38 H 1.08997 * 109.47172 * 299.99762 * 18 17 7 39 39 H 1.08998 * 109.47554 * 59.99767 * 18 17 7 40 40 H 1.09006 * 109.50603 * 297.54506 * 20 19 18 41 41 H 1.09003 * 109.50663 * 57.67164 * 20 19 18 42 42 H 1.08994 * 109.50511 * 296.91476 * 21 20 19 43 43 H 1.08995 * 109.54235 * 176.80143 * 21 20 19 44 44 H 1.08996 * 109.50161 * 298.73680 * 23 22 21 45 45 H 1.09002 * 109.54009 * 178.63053 * 23 22 21 46 46 H 1.08999 * 109.50620 * 302.32609 * 24 19 18 47 47 H 1.08999 * 109.51226 * 62.41126 * 24 19 18 48 48 H 1.09003 * 113.61537 * 203.74923 * 25 2 1 49 49 H 1.08998 * 113.62060 * 334.65724 * 25 2 1 50 50 H 1.09001 * 113.53348 * 270.80488 * 26 25 2 51 51 H 1.09000 * 113.74407 * 139.94640 * 26 25 2 52 52 H 1.08995 * 113.61952 * 25.34501 * 27 2 1 53 53 H 1.09005 * 113.61383 * 156.24773 * 27 2 1 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 8 2.0848 1.3169 0.0000 4 6 1.5425 2.1761 1.0049 5 6 2.1962 3.5308 0.9137 6 8 3.0466 3.7386 0.0743 7 7 1.8394 4.5102 1.7682 8 6 0.8118 4.2595 2.7818 9 6 1.4622 3.7444 4.0398 10 1 2.5338 3.6162 4.0801 11 6 0.6891 3.4358 5.1390 12 7 -0.6160 3.5905 5.0894 13 14 1.4955 2.7980 6.6986 14 1 2.9644 2.7143 6.4978 15 1 1.2009 3.7233 7.8221 16 1 0.9619 1.4488 7.0156 17 6 2.4791 5.8254 1.6833 18 6 1.6837 6.7188 0.7294 19 7 2.3249 8.0378 0.6448 20 6 2.2414 8.7476 1.9296 21 6 2.9718 10.0882 1.8143 22 8 2.4045 10.8435 0.7405 23 6 2.4694 10.1822 -0.5259 24 6 1.7339 8.8426 -0.4342 25 6 2.1461 -0.9280 1.0602 26 6 2.0951 -2.0419 -0.0014 27 6 2.1460 -0.9279 -1.0603 28 1 -0.3633 0.3570 -0.9636 29 1 -0.3632 -1.0132 0.1726 30 1 -0.3633 0.6558 0.7911 31 1 1.7309 1.7478 1.9894 32 1 0.4682 2.2797 0.8533 33 1 0.2826 5.1871 2.9999 34 1 0.1059 3.5177 2.4078 35 1 -1.1598 3.3738 5.8628 36 1 2.5040 6.2818 2.6728 37 1 3.4969 5.7110 1.3103 38 1 1.6588 6.2624 -0.2601 39 1 0.6659 6.8332 1.1024 40 1 1.1954 8.9234 2.1810 41 1 2.7074 8.1450 2.7092 42 1 4.0288 9.9108 1.6160 43 1 2.8644 10.6432 2.7462 44 1 3.5119 10.0077 -0.7922 45 1 1.9986 10.8047 -1.2868 46 1 1.8296 8.3095 -1.3801 47 1 0.6797 9.0194 -0.2211 48 1 3.1586 -0.6476 1.3506 49 1 1.4940 -1.1080 1.9149 50 1 1.1596 -2.6013 -0.0007 51 1 2.9739 -2.6868 -0.0033 52 1 1.4940 -1.1078 -1.9150 53 1 3.1586 -0.6475 -1.3507 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 ZINC000746151130.mol2 53 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 06:08:48 Heat of formation + Delta-G solvation = -97.002069 kcal Electronic energy + Delta-G solvation = -31117.043077 eV Core-core repulsion = 26989.874493 eV Total energy + Delta-G solvation = -4127.168584 eV No. of doubly occupied orbitals = 66 Molecular weight (most abundant/longest-lived isotopes) = 340.220 amu Computer time = 0.81 seconds Orbital eigenvalues (eV) -39.87636 -39.56710 -38.80204 -36.21045 -35.38095 -34.77775 -32.67580 -31.24540 -30.16255 -28.98803 -27.72922 -27.30372 -25.74298 -25.32709 -24.02644 -23.17445 -22.96815 -21.79553 -20.31448 -18.66885 -18.46711 -17.05992 -16.77524 -16.55780 -16.16354 -15.97556 -15.53138 -15.34396 -15.13526 -15.03169 -14.89636 -14.62856 -14.39344 -14.16250 -13.72397 -13.41881 -13.15263 -13.08000 -12.56045 -12.44513 -12.30255 -12.16223 -12.06782 -11.93567 -11.67100 -11.52958 -11.43041 -11.36662 -11.19611 -10.99629 -10.95429 -10.86998 -10.69415 -10.62965 -10.40849 -10.20106 -10.05323 -9.84488 -9.68289 -9.14515 -8.98233 -8.63574 -8.34826 -7.79620 -6.27255 -4.35229 3.15739 3.24855 3.27408 3.34380 3.36333 3.77560 3.93389 4.24210 4.42472 4.64370 4.67061 4.84675 4.85249 4.90590 5.00169 5.02503 5.06115 5.12415 5.25599 5.34796 5.37298 5.50711 5.53492 5.55388 5.56078 5.62801 5.68623 5.75950 5.76374 5.80421 5.82539 5.86839 5.92978 5.94643 5.95482 5.98759 6.09723 6.12627 6.25455 6.31203 6.42938 6.45976 6.62628 6.98785 7.02083 7.05728 7.10454 7.39707 7.59823 7.68146 7.95448 8.24256 8.71549 8.97887 9.33797 10.79309 Molecular weight = 340.22amu Principal moments of inertia in cm(-1) A = 0.008533 B = 0.003430 C = 0.002597 Principal moments of inertia in units of 10**(-40)*gram-cm**2 A = 3280.589811 B = 8161.260714 C =10779.117527 Net atomic charges, atomic populations, and dipole contributions calculated with CM2 Atom NO. Type Charge No. of electrons 1 C -0.165 4.165 2 C 0.086 3.914 3 O -0.351 6.351 4 C 0.048 3.952 5 C 0.519 3.481 6 O -0.552 6.552 7 N -0.596 5.596 8 C 0.236 3.764 9 C -0.540 4.540 10 H 0.063 0.937 11 C 0.067 3.933 12 N -0.891 5.891 13 Si 0.895 3.105 14 H -0.271 1.271 15 H -0.282 1.282 16 H -0.282 1.282 17 C 0.129 3.871 18 C 0.044 3.956 19 N -0.533 5.533 20 C 0.012 3.988 21 C 0.065 3.935 22 O -0.389 6.389 23 C 0.065 3.935 24 C 0.018 3.982 25 C -0.162 4.162 26 C -0.140 4.140 27 C -0.119 4.119 28 H 0.065 0.935 29 H 0.068 0.932 30 H 0.071 0.929 31 H 0.091 0.909 32 H 0.076 0.924 33 H 0.036 0.964 34 H 0.036 0.964 35 H 0.265 0.735 36 H 0.078 0.922 37 H 0.081 0.919 38 H 0.076 0.924 39 H 0.038 0.962 40 H 0.044 0.956 41 H 0.093 0.907 42 H 0.059 0.941 43 H 0.097 0.903 44 H 0.059 0.941 45 H 0.095 0.905 46 H 0.085 0.915 47 H 0.041 0.959 48 H 0.089 0.911 49 H 0.071 0.929 50 H 0.080 0.920 51 H 0.071 0.929 52 H 0.071 0.929 53 H 0.090 0.910 For the charges calculated by CM2: Dipole moment (debyes) X Y Z Total from point charges 1.673 0.982 -8.819 9.030 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 -0.222 4.222 2 C 0.046 3.954 3 O -0.270 6.270 4 C -0.031 4.031 5 C 0.307 3.693 6 O -0.431 6.431 7 N -0.328 5.328 8 C 0.117 3.883 9 C -0.578 4.578 10 H 0.081 0.919 11 C -0.137 4.137 12 N -0.529 5.529 13 Si 0.722 3.278 14 H -0.195 1.195 15 H -0.208 1.208 16 H -0.208 1.208 17 C 0.005 3.995 18 C -0.084 4.084 19 N -0.259 5.259 20 C -0.116 4.116 21 C -0.012 4.012 22 O -0.308 6.308 23 C -0.012 4.012 24 C -0.110 4.110 25 C -0.200 4.200 26 C -0.177 4.177 27 C -0.157 4.157 28 H 0.084 0.916 29 H 0.087 0.913 30 H 0.089 0.911 31 H 0.109 0.891 32 H 0.094 0.906 33 H 0.054 0.946 34 H 0.054 0.946 35 H 0.075 0.925 36 H 0.096 0.904 37 H 0.099 0.901 38 H 0.095 0.905 39 H 0.056 0.944 40 H 0.062 0.938 41 H 0.111 0.889 42 H 0.078 0.922 43 H 0.115 0.885 44 H 0.077 0.923 45 H 0.113 0.887 46 H 0.103 0.897 47 H 0.059 0.941 48 H 0.108 0.892 49 H 0.090 0.910 50 H 0.099 0.901 51 H 0.090 0.910 52 H 0.090 0.910 53 H 0.108 0.892 Dipole moment (debyes) X Y Z Total from point charges 2.491 1.237 -9.352 9.756 hybrid contribution -0.864 -0.629 1.506 1.847 sum 1.626 0.608 -7.845 8.035 Atomic orbital electron populations 1.22117 0.94007 1.02973 1.03100 1.22978 0.92912 0.82305 0.97196 1.88014 1.63143 1.21416 1.54411 1.22224 0.97744 0.89714 0.93442 1.20112 0.82630 0.85664 0.80900 1.90625 1.33088 1.82530 1.36888 1.48093 1.41036 1.10188 1.33513 1.19464 0.85699 0.97717 0.85468 1.21540 0.94319 1.44701 0.97271 0.91869 1.24936 0.94739 0.95177 0.98819 1.69926 1.04200 1.47863 1.30886 0.86479 0.79809 0.78655 0.82833 1.19546 1.20771 1.20765 1.21151 0.96962 0.82489 0.98931 1.22512 0.96238 0.88425 1.01274 1.62137 1.56290 1.03008 1.04448 1.22884 1.00297 0.95783 0.92652 1.22681 0.96952 0.91210 0.90388 1.87955 1.81937 1.43974 1.16920 1.22642 1.00318 0.92359 0.85863 1.22761 0.97135 0.94974 0.96139 1.23623 1.02440 0.96430 0.97526 1.22715 1.02099 0.96089 0.96802 1.23043 1.02082 0.94096 0.96433 0.91623 0.91260 0.91060 0.89142 0.90617 0.94602 0.94595 0.92500 0.90407 0.90071 0.90549 0.94392 0.93759 0.88869 0.92245 0.88501 0.92277 0.88704 0.89687 0.94063 0.89219 0.91021 0.90131 0.91029 0.91043 0.89151 Number of geometries 1 Number of calculations of the screened coulomb radii 1 The total number of SCF iterations 13. 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 -0.16 -2.12 8.80 37.16 0.33 -1.79 16 2 C 0.09 1.26 1.39 -89.81 -0.12 1.13 16 3 O -0.35 -6.59 9.83 -55.14 -0.54 -7.13 16 4 C 0.05 0.92 4.35 36.00 0.16 1.08 16 5 C 0.52 11.18 7.75 -10.98 -0.09 11.10 16 6 O -0.55 -13.17 16.08 -14.35 -0.23 -13.40 16 7 N -0.60 -12.38 2.46 -175.06 -0.43 -12.81 16 8 C 0.24 5.39 4.96 -5.19 -0.03 5.36 16 9 C -0.54 -13.52 9.27 -34.44 -0.32 -13.84 16 10 H 0.06 1.63 7.81 -52.49 -0.41 1.22 16 11 C 0.07 1.70 5.46 -17.82 -0.10 1.60 16 12 N -0.89 -23.66 13.29 55.43 0.74 -22.93 16 13 Si 0.89 19.98 29.54 -169.99 -5.02 14.95 16 14 H -0.27 -6.06 7.11 56.52 0.40 -5.66 16 15 H -0.28 -6.28 7.11 56.52 0.40 -5.88 16 16 H -0.28 -6.25 7.11 56.52 0.40 -5.85 16 17 C 0.13 2.38 5.34 -4.04 -0.02 2.36 16 18 C 0.04 0.72 5.28 -3.82 -0.02 0.70 16 19 N -0.53 -7.70 4.73 -234.31 -1.11 -8.81 16 20 C 0.01 0.16 5.44 -3.71 -0.02 0.14 16 21 C 0.06 0.76 7.01 37.21 0.26 1.02 16 22 O -0.39 -5.04 10.83 -35.23 -0.38 -5.42 16 23 C 0.07 0.72 7.01 37.21 0.26 0.98 16 24 C 0.02 0.23 5.64 -3.71 -0.02 0.21 16 25 C -0.16 -2.19 7.33 -25.83 -0.19 -2.38 16 26 C -0.14 -1.50 7.74 -25.83 -0.20 -1.70 16 27 C -0.12 -1.46 7.50 -25.92 -0.19 -1.65 16 28 H 0.06 0.80 8.14 -51.93 -0.42 0.37 16 29 H 0.07 0.75 7.34 -51.93 -0.38 0.37 16 30 H 0.07 0.99 6.27 -51.93 -0.33 0.67 16 31 H 0.09 1.81 7.92 -51.93 -0.41 1.40 16 32 H 0.08 1.37 5.64 -51.93 -0.29 1.08 16 33 H 0.04 0.86 8.07 -51.93 -0.42 0.44 16 34 H 0.04 0.84 6.44 -51.92 -0.33 0.50 16 35 H 0.27 6.71 8.31 -40.82 -0.34 6.37 16 36 H 0.08 1.42 6.44 -51.93 -0.33 1.08 16 37 H 0.08 1.59 7.42 -51.93 -0.39 1.20 16 38 H 0.08 1.32 8.04 -51.93 -0.42 0.90 16 39 H 0.04 0.64 8.12 -51.93 -0.42 0.22 16 40 H 0.04 0.62 8.14 -51.93 -0.42 0.20 16 41 H 0.09 1.25 6.38 -51.93 -0.33 0.92 16 42 H 0.06 0.67 8.14 -51.93 -0.42 0.25 16 43 H 0.10 0.96 8.14 -51.93 -0.42 0.54 16 44 H 0.06 0.64 8.14 -51.93 -0.42 0.22 16 45 H 0.09 0.84 8.14 -51.93 -0.42 0.42 16 46 H 0.08 0.99 8.09 -51.93 -0.42 0.57 16 47 H 0.04 0.53 8.14 -51.93 -0.42 0.10 16 48 H 0.09 1.29 8.14 -51.93 -0.42 0.87 16 49 H 0.07 0.95 8.10 -51.93 -0.42 0.53 16 50 H 0.08 0.76 7.64 -51.93 -0.40 0.36 16 51 H 0.07 0.69 8.14 -51.93 -0.42 0.27 16 52 H 0.07 0.77 8.10 -51.93 -0.42 0.35 16 53 H 0.09 1.16 8.14 -51.93 -0.42 0.74 16 LS Contribution 415.88 15.07 6.27 6.27 Total: -1.00 -29.68 415.88 -10.51 -40.19 By element: Atomic # 1 Polarization: 14.26 SS G_CDS: -9.48 Total: 4.77 kcal Atomic # 6 Polarization: 4.62 SS G_CDS: -0.31 Total: 4.31 kcal Atomic # 7 Polarization: -43.74 SS G_CDS: -0.80 Total: -44.54 kcal Atomic # 8 Polarization: -24.80 SS G_CDS: -1.15 Total: -25.95 kcal Atomic # 14 Polarization: 19.98 SS G_CDS: -5.02 Total: 14.95 kcal Total LS contribution 6.27 Total: 6.27 kcal Total: -29.68 -10.51 -40.19 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. ZINC000746151130.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 -56.811 kcal (2) G-P(sol) polarization free energy of solvation -29.683 kcal (3) G-ENP(sol) elect.-nuc.-pol. free energy of system -86.494 kcal (4) G-CDS(sol) cavity-dispersion-solvent structure free energy -10.508 kcal (5) G-P-CDS(sol) = G-P(sol) + G-CDS(sol) = (2) + (4) -40.191 kcal (6) G-S(sol) free energy of system = (1) + (5) -97.002 kcal 1SCF WAS SPECIFIED, SO GEOMETRY OPTIMIZATION WAS NOT USED Total computer time = 0.82 seconds