Wall clock time and date at job start Mon Mar 8 2021 09:06:31 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= 0 * 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 1.52996 * 1 3 3 C 1.52991 * 109.47255 * 2 1 4 4 C 1.53000 * 109.47016 * 239.99411 * 2 1 3 5 5 Si 1.86307 * 109.47159 * 120.00066 * 2 1 3 6 6 C 1.86302 * 109.46888 * 300.00004 * 5 2 1 7 7 C 1.86295 * 109.47173 * 179.97438 * 5 2 1 8 8 O 1.63098 * 109.46929 * 59.99474 * 5 2 1 9 9 C 1.35994 * 114.00105 * 180.02562 * 8 5 2 10 10 C 1.38713 * 119.98167 * 89.99986 * 9 8 5 11 11 C 1.38098 * 120.01769 * 180.02562 * 10 9 8 12 12 C 1.38867 * 119.98310 * 359.97438 * 11 10 9 13 13 N 1.39983 * 120.02384 * 180.02562 * 12 11 10 14 14 C 1.39188 * 120.00366 * 146.89707 * 13 12 11 15 15 C 1.39310 * 119.71853 * 174.44286 * 14 13 12 16 16 F 1.35099 * 120.47147 * 0.02562 * 15 14 13 17 17 C 1.38495 * 119.05672 * 180.02562 * 15 14 13 18 18 C 1.38858 * 118.48455 * 359.97438 * 17 15 14 19 19 C 1.50703 * 120.32616 * 179.97438 * 18 17 15 20 20 O 1.42897 * 109.47345 * 300.02264 * 19 18 17 21 21 Si 1.86300 * 109.47137 * 180.02562 * 19 18 17 22 22 H 1.48507 * 109.47315 * 300.00358 * 21 19 18 23 23 H 1.48504 * 109.46979 * 60.00241 * 21 19 18 24 24 H 1.48498 * 109.47247 * 179.97438 * 21 19 18 25 25 C 1.38051 * 119.35054 * 359.97438 * 18 17 15 26 26 N 1.31965 * 120.89748 * 0.02562 * 25 18 17 27 27 C 1.38877 * 119.96029 * 0.27636 * 12 11 10 28 28 C 1.38099 * 119.98182 * 359.48962 * 27 12 11 29 29 H 1.08999 * 109.46953 * 300.00111 * 1 2 3 30 30 H 1.09001 * 109.47256 * 59.99886 * 1 2 3 31 31 H 1.08998 * 109.47627 * 180.02562 * 1 2 3 32 32 H 1.09003 * 109.47292 * 179.97438 * 3 2 1 33 33 H 1.08997 * 109.47097 * 299.99717 * 3 2 1 34 34 H 1.08999 * 109.47231 * 60.00058 * 3 2 1 35 35 H 1.08995 * 109.47479 * 300.00804 * 4 2 1 36 36 H 1.09001 * 109.46534 * 60.00261 * 4 2 1 37 37 H 1.09004 * 109.47059 * 179.97438 * 4 2 1 38 38 H 1.09001 * 109.46801 * 180.02562 * 6 5 2 39 39 H 1.08998 * 109.46590 * 299.99680 * 6 5 2 40 40 H 1.08998 * 109.47295 * 59.99587 * 6 5 2 41 41 H 1.08999 * 109.47209 * 299.99987 * 7 5 2 42 42 H 1.09005 * 109.46937 * 60.00434 * 7 5 2 43 43 H 1.08997 * 109.46850 * 179.97438 * 7 5 2 44 44 H 1.07999 * 119.98921 * 0.02562 * 10 9 8 45 45 H 1.08002 * 120.00792 * 179.97438 * 11 10 9 46 46 H 0.97005 * 119.99548 * 326.91291 * 13 12 11 47 47 H 1.07995 * 120.75946 * 179.97438 * 17 15 14 48 48 H 1.08999 * 109.46609 * 60.02540 * 19 18 17 49 49 H 0.96695 * 113.99702 * 179.97438 * 20 19 18 50 50 H 1.07992 * 119.54943 * 179.97438 * 25 18 17 51 51 H 1.08001 * 120.01213 * 179.72438 * 27 12 11 52 52 H 1.07996 * 119.98886 * 180.22976 * 28 27 12 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 6 2.0400 1.4424 0.0000 4 6 2.0399 -0.7214 -1.2492 5 14 2.1510 -0.8783 1.5212 6 6 1.5300 0.0000 3.0423 7 6 4.0139 -0.8790 1.5208 8 8 1.6072 -2.4159 1.5212 9 6 2.0080 -3.1444 2.5974 10 6 1.2311 -3.1687 3.7462 11 6 1.6376 -3.9077 4.8397 12 6 2.8243 -4.6272 4.7887 13 7 3.2369 -5.3770 5.8963 14 6 3.9400 -6.5638 5.7106 15 6 4.4485 -7.2453 6.8141 16 9 4.2634 -6.7626 8.0623 17 6 5.1464 -8.4246 6.6135 18 6 5.3118 -8.8832 5.3133 19 6 6.0646 -10.1613 5.0472 20 8 7.4009 -10.0381 5.5382 21 14 6.1046 -10.4883 3.2135 22 1 4.7158 -10.6163 2.7031 23 1 6.7833 -9.3614 2.5245 24 1 6.8469 -11.7474 2.9513 25 6 4.7798 -8.1569 4.2667 26 7 4.1189 -7.0360 4.4867 27 6 3.6041 -4.5981 3.6399 28 6 3.1937 -3.8624 2.5456 29 1 -0.3633 0.5138 0.8900 30 1 -0.3634 0.5139 -0.8900 31 1 -0.3634 -1.0276 0.0005 32 1 3.1300 1.4424 0.0005 33 1 1.6767 1.9562 -0.8900 34 1 1.6767 1.9563 0.8900 35 1 1.6765 -1.7490 -1.2492 36 1 1.6766 -0.2075 -2.1391 37 1 3.1300 -0.7210 -1.2494 38 1 1.8937 -0.5136 3.9323 39 1 1.8934 1.0276 3.0422 40 1 0.4400 0.0001 3.0423 41 1 4.3769 -1.3930 0.6308 42 1 4.3776 0.1486 1.5206 43 1 4.3772 -1.3924 2.4110 44 1 0.3080 -2.6095 3.7856 45 1 1.0328 -3.9262 5.7342 46 1 3.0326 -5.0696 6.7934 47 1 5.5527 -8.9749 7.4491 48 1 5.5664 -10.9884 5.5530 49 1 7.9445 -10.8259 5.4009 50 1 4.9068 -8.5104 3.2543 51 1 4.5294 -5.1537 3.6009 52 1 3.7982 -3.8427 1.6509 RHF calculation, no. of doubly occupied orbitals= 68 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) F: (AM1): M.J.S. DEWAR AND E. G. ZOEBISCH, THEOCHEM, 180, 1 (1988). 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=0 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 s_27_16978794_17656566.mol2 52 1SCF WAS SPECIFIED, SO GEOMETRY OPTIMIZATION WAS NOT USED SCF FIELD WAS ACHIEVED Wall clock time and date at job start Mon Mar 8 2021 09:06:31 Heat of formation + Delta-G solvation = -91.040675 kcal Electronic energy + Delta-G solvation = -32406.971998 eV Core-core repulsion = 28023.755239 eV Total energy + Delta-G solvation = -4383.216759 eV No. of doubly occupied orbitals = 68 Molecular weight (most abundant/longest-lived isotopes) = 378.169 amu Computer time = 1.21 seconds Orbital eigenvalues (eV) -49.95116 -41.72940 -40.70261 -38.65901 -37.72803 -36.88435 -35.85855 -33.45695 -32.05974 -31.86535 -29.56647 -29.08557 -29.03408 -27.89737 -27.40496 -26.63116 -25.12149 -23.83308 -23.12932 -22.48025 -20.51286 -19.56874 -18.96644 -18.81488 -18.58010 -18.07219 -17.42438 -17.00024 -16.71986 -16.46775 -16.23254 -15.98137 -15.92290 -15.20550 -15.12515 -14.96174 -14.88450 -14.79498 -14.71508 -14.47356 -14.18893 -14.06246 -13.92971 -13.79332 -13.61848 -13.44145 -13.37154 -13.24242 -13.10696 -12.94941 -12.93925 -12.68324 -12.44403 -12.35844 -12.15368 -12.10488 -11.85859 -11.74464 -11.63345 -11.58377 -10.82615 -10.71831 -10.48916 -10.42694 -10.12248 -9.86377 -9.67785 -8.39075 -0.26013 -0.02799 0.44563 0.47379 1.01880 1.33354 1.40254 1.41850 1.66875 1.81051 1.81226 1.98460 2.36678 2.45668 2.91317 2.95022 3.12340 3.27983 3.56115 3.76772 3.92920 4.02021 4.05981 4.08344 4.08473 4.19873 4.30963 4.37436 4.43163 4.48687 4.57430 4.63760 4.70012 4.72085 4.73969 4.76687 4.78906 4.82825 4.87004 4.93273 4.97162 5.07359 5.07698 5.09578 5.17706 5.28012 5.31708 5.39637 5.42439 5.43543 5.51991 5.54036 5.59580 5.63480 5.91789 6.09592 6.29553 6.45900 6.84956 Net atomic charges, atomic populations, and dipole contributions calculated with CM2 Atom NO. Type Charge No. of electrons 1 C -0.136 4.136 2 C -0.372 4.372 3 C -0.137 4.137 4 C -0.136 4.136 5 Si 1.279 2.721 6 C -0.506 4.506 7 C -0.507 4.507 8 O -0.560 6.560 9 C 0.112 3.888 10 C -0.134 4.134 11 C -0.126 4.126 12 C 0.145 3.855 13 N -0.656 5.656 14 C 0.375 3.625 15 C -0.006 4.006 16 F -0.130 7.130 17 C -0.035 4.035 18 C -0.152 4.152 19 C -0.071 4.071 20 O -0.545 6.545 21 Si 0.936 3.064 22 H -0.245 1.245 23 H -0.242 1.242 24 H -0.251 1.251 25 C 0.137 3.863 26 N -0.496 5.496 27 C -0.094 4.094 28 C -0.134 4.134 29 H 0.055 0.945 30 H 0.055 0.945 31 H 0.059 0.941 32 H 0.057 0.943 33 H 0.057 0.943 34 H 0.057 0.943 35 H 0.060 0.940 36 H 0.055 0.945 37 H 0.055 0.945 38 H 0.071 0.929 39 H 0.075 0.925 40 H 0.073 0.927 41 H 0.073 0.927 42 H 0.075 0.925 43 H 0.071 0.929 44 H 0.134 0.866 45 H 0.130 0.870 46 H 0.423 0.577 47 H 0.154 0.846 48 H 0.081 0.919 49 H 0.383 0.617 50 H 0.160 0.840 51 H 0.140 0.860 52 H 0.134 0.866 For the charges calculated by CM2: Dipole moment (debyes) X Y Z Total from point charges 1.053 -1.961 0.460 2.273 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 -0.193 4.193 2 C -0.416 4.416 3 C -0.194 4.194 4 C -0.193 4.193 5 Si 1.413 2.587 6 C -0.609 4.609 7 C -0.609 4.609 8 O -0.514 6.514 9 C 0.068 3.932 10 C -0.153 4.153 11 C -0.147 4.147 12 C 0.050 3.950 13 N -0.282 5.282 14 C 0.139 3.861 15 C -0.032 4.032 16 F -0.109 7.109 17 C -0.062 4.062 18 C -0.157 4.157 19 C -0.182 4.182 20 O -0.352 6.352 21 Si 0.758 3.242 22 H -0.168 1.168 23 H -0.166 1.166 24 H -0.174 1.174 25 C -0.020 4.020 26 N -0.211 5.211 27 C -0.114 4.114 28 C -0.154 4.154 29 H 0.074 0.926 30 H 0.074 0.926 31 H 0.078 0.922 32 H 0.076 0.924 33 H 0.077 0.923 34 H 0.076 0.924 35 H 0.079 0.921 36 H 0.074 0.926 37 H 0.074 0.926 38 H 0.090 0.910 39 H 0.094 0.906 40 H 0.092 0.908 41 H 0.092 0.908 42 H 0.094 0.906 43 H 0.090 0.910 44 H 0.152 0.848 45 H 0.148 0.852 46 H 0.261 0.739 47 H 0.172 0.828 48 H 0.099 0.901 49 H 0.231 0.769 50 H 0.177 0.823 51 H 0.158 0.842 52 H 0.152 0.848 Dipole moment (debyes) X Y Z Total from point charges 0.314 -1.183 -1.185 1.704 hybrid contribution 0.506 -0.378 1.704 1.818 sum 0.820 -1.561 0.519 1.838 Atomic orbital electron populations 1.21532 0.93719 1.02075 1.01956 1.25740 1.00758 1.02705 1.12427 1.21555 1.00856 0.94735 1.02257 1.21534 1.00720 1.00264 0.96776 0.77026 0.63657 0.52585 0.65406 1.26996 1.06932 1.09336 1.17620 1.27001 1.24256 1.04829 1.04840 1.83822 1.77995 1.45063 1.44509 1.17995 0.93557 0.96077 0.85620 1.21028 1.00852 1.01547 0.91879 1.20697 0.94575 0.99948 0.99506 1.17609 0.93803 0.95117 0.88513 1.41934 1.57716 1.20011 1.08519 1.18358 0.91717 0.87206 0.88816 1.17934 1.07841 0.97902 0.79539 1.91510 1.93981 1.87619 1.37792 1.21281 0.93577 0.92873 0.98428 1.19942 1.03591 0.98949 0.93188 1.24522 0.85174 0.96830 1.11636 1.86498 1.21493 1.43124 1.84043 0.85875 0.82185 0.81547 0.74591 1.16811 1.16556 1.17448 1.22391 0.91962 0.88686 0.98980 1.67506 1.19205 1.14615 1.19789 1.20982 0.99961 0.98496 0.92005 1.21156 0.96154 0.98755 0.99290 0.92595 0.92607 0.92159 0.92430 0.92350 0.92440 0.92146 0.92616 0.92576 0.90973 0.90563 0.90807 0.90787 0.90578 0.90970 0.84768 0.85228 0.73869 0.82831 0.90133 0.76920 0.82282 0.84243 0.84829 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 -0.14 -0.02 7.85 37.16 0.29 0.27 16 2 C -0.37 0.02 0.53 -90.63 -0.05 -0.02 16 3 C -0.14 0.07 7.85 37.15 0.29 0.37 16 4 C -0.14 -0.03 7.85 37.16 0.29 0.26 16 5 Si 1.28 -0.32 8.27 -169.99 -1.41 -1.73 16 6 C -0.51 0.10 8.31 101.05 0.84 0.94 16 7 C -0.51 -0.01 8.31 101.05 0.84 0.83 16 8 O -0.56 -0.97 8.52 -19.72 -0.17 -1.14 16 9 C 0.11 0.23 4.64 -39.23 -0.18 0.04 16 10 C -0.13 -0.16 8.76 -39.46 -0.35 -0.51 16 11 C -0.13 -0.10 9.96 -39.40 -0.39 -0.49 16 12 C 0.14 0.26 6.30 -83.67 -0.53 -0.27 16 13 N -0.66 -0.71 5.49 -9.87 -0.05 -0.77 16 14 C 0.37 0.81 7.21 -154.78 -1.12 -0.31 16 15 C -0.01 -0.01 7.35 -39.09 -0.29 -0.30 16 16 F -0.13 -0.24 16.66 2.25 0.04 -0.20 16 17 C -0.04 -0.02 9.75 -39.26 -0.38 -0.41 16 18 C -0.15 -0.05 5.43 -104.46 -0.57 -0.62 16 19 C -0.07 0.13 2.83 36.01 0.10 0.23 16 20 O -0.55 0.70 12.75 -35.23 -0.45 0.25 16 21 Si 0.94 -1.83 25.10 -169.99 -4.27 -6.10 16 22 H -0.24 0.34 7.11 56.52 0.40 0.74 16 23 H -0.24 0.15 7.11 56.52 0.40 0.55 16 24 H -0.25 0.43 7.11 56.52 0.40 0.84 16 25 C 0.14 0.14 9.84 -17.56 -0.17 -0.03 16 26 N -0.50 -1.25 7.11 -12.35 -0.09 -1.34 16 27 C -0.09 -0.21 8.57 -39.40 -0.34 -0.55 16 28 C -0.13 -0.25 8.76 -39.46 -0.35 -0.60 16 29 H 0.06 -0.03 7.79 -51.93 -0.40 -0.43 16 30 H 0.05 0.01 8.14 -51.93 -0.42 -0.41 16 31 H 0.06 0.03 7.96 -51.93 -0.41 -0.39 16 32 H 0.06 -0.07 7.79 -51.93 -0.40 -0.47 16 33 H 0.06 -0.02 8.14 -51.93 -0.42 -0.44 16 34 H 0.06 -0.07 7.79 -51.93 -0.40 -0.47 16 35 H 0.06 0.03 7.96 -51.93 -0.41 -0.38 16 36 H 0.05 0.02 8.14 -51.93 -0.42 -0.41 16 37 H 0.06 -0.02 7.79 -51.93 -0.40 -0.43 16 38 H 0.07 0.00 7.38 -51.93 -0.38 -0.38 16 39 H 0.08 -0.05 7.79 -51.93 -0.40 -0.46 16 40 H 0.07 -0.03 7.79 -51.93 -0.40 -0.43 16 41 H 0.07 -0.01 7.79 -51.93 -0.40 -0.41 16 42 H 0.08 -0.04 7.79 -51.93 -0.40 -0.45 16 43 H 0.07 0.03 7.37 -51.93 -0.38 -0.35 16 44 H 0.13 -0.03 8.06 -52.49 -0.42 -0.45 16 45 H 0.13 -0.16 8.06 -52.49 -0.42 -0.58 16 46 H 0.42 -0.35 8.30 -40.82 -0.34 -0.69 16 47 H 0.15 -0.12 8.06 -52.49 -0.42 -0.55 16 48 H 0.08 -0.30 7.96 -51.93 -0.41 -0.71 16 49 H 0.38 -2.13 8.74 45.56 0.40 -1.73 16 50 H 0.16 -0.11 4.88 -52.49 -0.26 -0.37 16 51 H 0.14 0.33 6.28 -52.49 -0.33 0.00 16 52 H 0.13 0.08 8.06 -52.49 -0.42 -0.34 16 LS Contribution 421.14 15.07 6.35 6.35 Total: 0.00 -5.82 421.14 -9.62 -15.44 By element: Atomic # 1 Polarization: -2.09 SS G_CDS: -7.52 Total: -9.61 kcal Atomic # 6 Polarization: 0.89 SS G_CDS: -2.05 Total: -1.16 kcal Atomic # 7 Polarization: -1.97 SS G_CDS: -0.14 Total: -2.11 kcal Atomic # 8 Polarization: -0.27 SS G_CDS: -0.62 Total: -0.89 kcal Atomic # 9 Polarization: -0.24 SS G_CDS: 0.04 Total: -0.20 kcal Atomic # 14 Polarization: -2.15 SS G_CDS: -5.67 Total: -7.83 kcal Total LS contribution 6.35 Total: 6.35 kcal Total: -5.82 -9.62 -15.44 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. s_27_16978794_17656566.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 -75.597 kcal (2) G-P(sol) polarization free energy of solvation -5.821 kcal (3) G-ENP(sol) elect.-nuc.-pol. free energy of system -81.418 kcal (4) G-CDS(sol) cavity-dispersion-solvent structure free energy -9.623 kcal (5) G-P-CDS(sol) = G-P(sol) + G-CDS(sol) = (2) + (4) -15.444 kcal (6) G-S(sol) free energy of system = (1) + (5) -91.041 kcal 1SCF WAS SPECIFIED, SO GEOMETRY OPTIMIZATION WAS NOT USED Total computer time = 1.21 seconds