Wall clock time and date at job start Sun Mar 7 2021 09:01:31 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 1.53002 * 109.47446 * 2 1 4 4 C 1.53006 * 109.47154 * 173.75884 * 3 2 1 5 5 C 1.52997 * 109.47454 * 293.76255 * 3 2 1 6 6 C 1.50693 * 109.47276 * 175.45733 * 5 3 2 7 7 O 1.21281 * 120.00470 * 118.01031 * 6 5 3 8 8 N 1.34786 * 119.99869 * 298.01178 * 6 5 3 9 9 C 1.46498 * 119.99764 * 185.03531 * 8 6 5 10 10 C 1.53007 * 109.46860 * 184.90105 * 9 8 6 11 11 F 1.39897 * 112.84816 * 43.23776 * 10 9 8 12 12 C 1.53776 * 113.61441 * 174.43262 * 10 9 8 13 13 C 1.53785 * 87.07996 * 139.98096 * 12 10 9 14 14 H 1.09005 * 113.61508 * 220.01993 * 13 12 10 15 15 C 1.52995 * 113.61032 * 89.20162 * 13 12 10 16 16 O 1.42900 * 109.46943 * 175.00177 * 15 13 12 17 17 C 1.53777 * 113.61430 * 271.93410 * 10 9 8 18 18 N 1.46499 * 109.46841 * 295.45626 * 5 3 2 19 19 C 1.36342 * 125.63638 * 295.06684 * 18 5 3 20 20 C 1.34855 * 108.21913 * 180.26678 * 19 18 5 21 21 C 1.40889 * 107.41580 * 359.73798 * 20 19 18 22 22 C 1.34854 * 107.41938 * 0.02562 * 21 20 19 23 23 C 1.50697 * 125.89175 * 179.97438 * 22 21 20 24 24 O 1.42898 * 109.47178 * 210.02188 * 23 22 21 25 25 Si 1.86299 * 109.47211 * 330.02261 * 23 22 21 26 26 H 1.08996 * 109.47106 * 304.86403 * 1 2 3 27 27 H 1.09007 * 109.47151 * 64.85519 * 1 2 3 28 28 H 1.08998 * 109.47440 * 184.85687 * 1 2 3 29 29 H 1.09005 * 109.47196 * 240.00061 * 2 1 3 30 30 H 1.08998 * 109.47422 * 120.00713 * 2 1 3 31 31 H 1.08999 * 109.46671 * 53.76433 * 3 2 1 32 32 H 1.08994 * 109.47056 * 170.67455 * 4 3 2 33 33 H 1.09005 * 109.46943 * 290.67407 * 4 3 2 34 34 H 1.09002 * 109.46985 * 50.66952 * 4 3 2 35 35 H 1.09002 * 109.47215 * 55.45076 * 5 3 2 36 36 H 0.97002 * 119.99596 * 5.03960 * 8 6 5 37 37 H 1.08998 * 109.47397 * 304.90304 * 9 8 6 38 38 H 1.08999 * 109.47364 * 64.90549 * 9 8 6 39 39 H 1.08994 * 113.61769 * 254.53086 * 12 10 9 40 40 H 1.09006 * 113.61571 * 25.35393 * 12 10 9 41 41 H 1.08998 * 109.47438 * 294.99803 * 15 13 12 42 42 H 1.08997 * 109.47667 * 55.00298 * 15 13 12 43 43 H 0.96702 * 114.00552 * 180.02562 * 16 15 13 44 44 H 1.08999 * 113.61680 * 334.56557 * 17 10 9 45 45 H 1.08995 * 113.61676 * 105.46920 * 17 10 9 46 46 H 1.08003 * 125.89460 * 359.97438 * 19 18 5 47 47 H 1.08000 * 126.29134 * 179.76468 * 20 19 18 48 48 H 1.08003 * 126.29013 * 179.97438 * 21 20 19 49 49 H 1.09003 * 109.46792 * 90.02578 * 23 22 21 50 50 H 0.96700 * 114.00357 * 179.97438 * 24 23 22 51 51 H 1.48494 * 110.00018 * 300.00057 * 25 23 22 52 52 H 1.48499 * 109.99948 * 61.31916 * 25 23 22 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 1.4425 0.0000 4 6 3.5620 1.4453 0.1568 5 6 1.6621 2.1172 -1.3202 6 6 2.0655 3.5684 -1.2761 7 8 2.8819 3.9952 -2.0650 8 7 1.5189 4.3923 -0.3600 9 6 1.8265 5.8243 -0.3867 10 6 1.1826 6.5069 0.8218 11 9 1.3360 5.7753 2.0044 12 6 1.5574 7.9916 0.9629 13 6 0.0949 8.2412 1.3673 14 1 -0.3246 9.1552 0.9467 15 6 -0.1563 8.1092 2.8708 16 8 -1.5079 8.4707 3.1614 17 6 -0.2597 6.9761 0.5682 18 7 2.3558 1.4508 -2.4251 19 6 3.7055 1.4278 -2.6171 20 6 3.9598 0.7243 -3.7392 21 6 2.7222 0.2923 -4.2556 22 6 1.7587 0.7487 -3.4298 23 6 0.2772 0.5261 -3.5926 24 8 -0.4348 1.6329 -3.0358 25 14 -0.1324 0.3721 -5.4035 26 1 -0.3633 0.5874 0.8432 27 1 -0.3634 0.4367 -0.9303 28 1 -0.3634 -1.0239 0.0870 29 1 1.8933 -0.5138 -0.8900 30 1 1.8933 -0.5139 0.8899 31 1 1.5884 1.9875 0.8289 32 1 3.9424 2.4532 -0.0082 33 1 3.8242 1.1182 1.1631 34 1 4.0037 0.7662 -0.5725 35 1 0.5850 2.0437 -1.4704 36 1 0.9220 4.0369 0.3170 37 1 2.9068 5.9647 -0.3504 38 1 1.4338 6.2633 -1.3038 39 1 2.2712 8.1876 1.7630 40 1 1.8378 8.4626 0.0207 41 1 0.0184 7.0785 3.1792 42 1 0.5209 8.7701 3.4117 43 1 -1.7383 8.4108 4.0987 44 1 -0.4776 7.1699 -0.4820 45 1 -1.0128 6.3524 1.0496 46 1 4.4434 1.8964 -1.9829 47 1 4.9332 0.5278 -4.1637 48 1 2.5725 -0.2956 -5.1492 49 1 -0.0117 -0.3890 -3.0756 50 1 -1.3963 1.5575 -3.1058 51 1 0.2568 1.6134 -6.1196 52 1 0.5771 -0.7946 -5.9872 There are 67 doubly filled levels RHF calculation, no. of doubly occupied orbitals= 67 No. of singly occupied orbitals= 1 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_22_16500644_12360566.mol2 52 1SCF WAS SPECIFIED, SO GEOMETRY OPTIMIZATION WAS NOT USED SCF FIELD WAS ACHIEVED Wall clock time and date at job start Sun Mar 7 2021 09:01:31 Heat of formation + Delta-G solvation = -83.845497 kcal Electronic energy + Delta-G solvation = -34560.005675 eV Core-core repulsion = 30056.691017 eV Total energy + Delta-G solvation = -4503.314658 eV No. of doubly occupied orbitals = 67 and no. of open levels = 1 Molecular weight (most abundant/longest-lived isotopes) = 355.199 amu Computer time = 1.27 seconds Orbital eigenvalues (eV) -49.02193 -42.76094 -40.62355 -39.89996 -37.88672 -37.68288 -37.25661 -35.64524 -33.03964 -31.56359 -30.83836 -30.42514 -28.25622 -27.24288 -26.60622 -25.83645 -24.68477 -23.05586 -22.20329 -21.65406 -21.40366 -20.33292 -19.92744 -19.03367 -18.46680 -18.35763 -17.69896 -17.24893 -17.17290 -16.89761 -16.73516 -16.20128 -15.92205 -15.68584 -15.56338 -15.36084 -15.16103 -14.98054 -14.81913 -14.72667 -14.45236 -14.32175 -14.15302 -13.83644 -13.70591 -13.59399 -13.51699 -13.34520 -13.20940 -13.01980 -12.88284 -12.70997 -12.58802 -12.25149 -11.96897 -11.94624 -11.92338 -11.79766 -11.67832 -11.63387 -11.44441 -10.98684 -10.88207 -10.54006 -10.25809 -9.41312 -8.71656 -4.96528 1.05223 1.44302 1.53803 1.68965 1.80650 2.11712 2.25194 2.30084 2.82422 2.93956 3.02846 3.07183 3.12311 3.32120 3.40383 3.53347 3.70457 3.75524 3.78216 3.94459 4.08456 4.17830 4.24933 4.29087 4.31780 4.34654 4.36981 4.38835 4.45097 4.47638 4.48125 4.53590 4.54008 4.59869 4.69001 4.72470 4.75615 4.79009 4.85802 4.92034 4.92890 5.01725 5.08680 5.13429 5.15347 5.22568 5.29016 5.45803 5.50494 6.14423 6.22255 6.39055 6.44968 6.55768 6.58017 7.05436 Net atomic charges, atomic populations, and dipole contributions calculated with CM2 Atom NO. Type Charge No. of electrons 1 C -0.162 4.162 2 C -0.119 4.119 3 C -0.097 4.097 4 C -0.165 4.165 5 C 0.111 3.889 6 C 0.511 3.489 7 O -0.519 6.519 8 N -0.724 5.724 9 C 0.114 3.886 10 C 0.078 3.922 11 F -0.184 7.184 12 C -0.142 4.142 13 C -0.111 4.111 14 H 0.097 0.903 15 C 0.085 3.915 16 O -0.573 6.573 17 C -0.146 4.146 18 N -0.406 5.406 19 C 0.024 3.976 20 C -0.205 4.205 21 C -0.197 4.197 22 C 0.027 3.973 23 C -0.044 4.044 24 O -0.553 6.553 25 Si 0.704 3.296 26 H 0.055 0.945 27 H 0.062 0.938 28 H 0.058 0.942 29 H 0.069 0.931 30 H 0.070 0.930 31 H 0.088 0.912 32 H 0.056 0.944 33 H 0.064 0.936 34 H 0.074 0.926 35 H 0.157 0.843 36 H 0.404 0.596 37 H 0.083 0.917 38 H 0.088 0.912 39 H 0.088 0.912 40 H 0.110 0.890 41 H 0.058 0.942 42 H 0.050 0.950 43 H 0.383 0.617 44 H 0.104 0.896 45 H 0.086 0.914 46 H 0.163 0.837 47 H 0.137 0.863 48 H 0.134 0.866 49 H 0.077 0.923 50 H 0.385 0.615 51 H -0.254 1.254 52 H -0.255 1.255 For the charges calculated by CM2: Dipole moment (debyes) X Y Z Total from point charges -5.396 -0.566 3.963 6.719 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 -0.219 4.219 2 C -0.156 4.156 3 C -0.117 4.117 4 C -0.222 4.222 5 C 0.005 3.995 6 C 0.296 3.704 7 O -0.393 6.393 8 N -0.378 5.378 9 C -0.010 4.010 10 C 0.060 3.940 11 F -0.164 7.164 12 C -0.180 4.180 13 C -0.129 4.129 14 H 0.115 0.885 15 C 0.007 3.993 16 O -0.379 6.379 17 C -0.184 4.184 18 N -0.082 5.082 19 C -0.106 4.106 20 C -0.229 4.229 21 C -0.222 4.222 22 C -0.084 4.084 23 C -0.154 4.154 24 O -0.361 6.361 25 Si 0.603 3.397 26 H 0.075 0.925 27 H 0.081 0.919 28 H 0.077 0.923 29 H 0.087 0.913 30 H 0.088 0.912 31 H 0.107 0.893 32 H 0.075 0.925 33 H 0.083 0.917 34 H 0.093 0.907 35 H 0.174 0.826 36 H 0.239 0.761 37 H 0.102 0.898 38 H 0.106 0.894 39 H 0.106 0.894 40 H 0.128 0.872 41 H 0.076 0.924 42 H 0.069 0.931 43 H 0.230 0.770 44 H 0.123 0.877 45 H 0.105 0.895 46 H 0.180 0.820 47 H 0.155 0.845 48 H 0.152 0.848 49 H 0.095 0.905 50 H 0.235 0.765 51 H -0.179 1.179 52 H -0.180 1.180 Dipole moment (debyes) X Y Z Total from point charges -4.065 0.200 2.334 4.692 hybrid contribution 0.421 -0.200 1.528 1.598 sum -3.644 -0.001 3.862 5.310 Atomic orbital electron populations 1.21931 0.95387 1.02282 1.02265 1.21560 0.96321 0.94745 1.02997 1.21567 0.97821 0.97760 0.94509 1.22240 0.94394 1.02456 1.03095 1.21803 1.01508 0.88824 0.87380 1.20628 0.81094 0.88089 0.80583 1.90786 1.31970 1.76904 1.39674 1.45714 1.50702 1.07874 1.33522 1.21830 1.01687 0.80426 0.97090 1.22228 0.98837 0.91412 0.81561 1.92839 1.96494 1.78702 1.48361 1.23575 0.97284 0.92871 1.04253 1.22248 0.95909 0.99884 0.94858 0.88510 1.22058 0.83454 0.99582 0.94160 1.86448 1.28755 1.91453 1.31216 1.23678 0.94861 0.97391 1.02421 1.43399 1.05641 1.39827 1.19346 1.21879 0.84091 1.04101 1.00530 1.20791 0.97982 1.06057 0.98063 1.20547 0.92496 1.08139 1.01057 1.19690 0.92182 1.03979 0.92549 1.24416 0.88051 0.91310 1.11596 1.86291 1.23357 1.43774 1.82661 0.95951 0.89724 0.80906 0.73119 0.92550 0.91873 0.92279 0.91256 0.91161 0.89337 0.92535 0.91658 0.90736 0.82646 0.76060 0.89848 0.89374 0.89366 0.87157 0.92414 0.93139 0.76965 0.87724 0.89538 0.82001 0.84474 0.84788 0.90497 0.76537 1.17877 1.17990 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 0.33 9.58 37.16 0.36 0.69 16 2 C -0.12 0.09 5.33 -26.73 -0.14 -0.05 16 3 C -0.10 0.05 2.16 -90.62 -0.20 -0.15 16 4 C -0.16 -0.07 7.56 37.16 0.28 0.21 16 5 C 0.11 0.13 2.24 -69.09 -0.15 -0.02 16 6 C 0.51 1.38 5.91 -10.98 -0.06 1.31 16 7 O -0.52 -3.49 15.12 5.56 0.08 -3.40 16 8 N -0.72 0.09 5.33 -60.29 -0.32 -0.24 16 9 C 0.11 -0.06 5.46 -4.04 -0.02 -0.08 16 10 C 0.08 -0.12 1.72 -89.81 -0.15 -0.28 16 11 F -0.18 0.00 14.85 2.25 0.03 0.03 16 12 C -0.14 0.33 7.13 -25.92 -0.18 0.14 16 13 C -0.11 0.15 4.19 -89.81 -0.38 -0.23 16 14 H 0.10 -0.09 8.14 -51.93 -0.42 -0.51 16 15 C 0.09 -0.07 6.66 37.15 0.25 0.17 16 16 O -0.57 -0.12 13.66 -35.23 -0.48 -0.60 16 17 C -0.15 0.27 7.07 -25.92 -0.18 0.09 16 18 N -0.41 -1.39 1.81 -106.71 -0.19 -1.58 16 19 C 0.02 0.11 7.19 -16.75 -0.12 -0.01 16 20 C -0.21 -0.98 10.86 -39.78 -0.43 -1.41 16 21 C -0.20 -0.93 9.43 -39.78 -0.37 -1.30 16 22 C 0.03 0.10 6.00 -81.79 -0.49 -0.39 16 23 C -0.04 0.01 2.53 36.00 0.09 0.10 16 24 O -0.55 0.81 8.83 -35.23 -0.31 0.50 16 25 Si 0.70 -0.28 31.25 -169.99 -5.31 -5.59 16 26 H 0.06 -0.15 8.14 -51.93 -0.42 -0.57 16 27 H 0.06 -0.14 5.11 -51.93 -0.27 -0.41 16 28 H 0.06 -0.12 8.14 -51.93 -0.42 -0.54 16 29 H 0.07 0.07 7.39 -51.93 -0.38 -0.31 16 30 H 0.07 -0.07 8.14 -51.93 -0.42 -0.49 16 31 H 0.09 -0.17 7.45 -51.93 -0.39 -0.56 16 32 H 0.06 0.09 6.72 -51.93 -0.35 -0.26 16 33 H 0.06 -0.03 8.14 -51.93 -0.42 -0.45 16 34 H 0.07 0.10 5.61 -51.93 -0.29 -0.19 16 35 H 0.16 0.03 3.55 -51.93 -0.18 -0.16 16 36 H 0.40 -0.78 7.44 -40.82 -0.30 -1.08 16 37 H 0.08 0.04 8.10 -51.93 -0.42 -0.38 16 38 H 0.09 -0.06 7.83 -51.93 -0.41 -0.46 16 39 H 0.09 -0.20 8.10 -51.93 -0.42 -0.62 16 40 H 0.11 -0.38 8.10 -51.93 -0.42 -0.81 16 41 H 0.06 -0.05 6.32 -51.93 -0.33 -0.37 16 42 H 0.05 -0.08 8.14 -51.93 -0.42 -0.50 16 43 H 0.38 -1.47 9.12 45.56 0.42 -1.05 16 44 H 0.10 -0.28 7.89 -51.93 -0.41 -0.69 16 45 H 0.09 -0.11 8.10 -51.93 -0.42 -0.53 16 46 H 0.16 0.61 6.20 -52.48 -0.33 0.28 16 47 H 0.14 0.45 8.06 -52.49 -0.42 0.03 16 48 H 0.13 0.53 6.74 -52.48 -0.35 0.17 16 49 H 0.08 -0.15 7.77 -51.93 -0.40 -0.56 16 50 H 0.39 -2.51 8.74 45.56 0.40 -2.11 16 51 H -0.25 -1.05 7.11 56.52 0.40 -0.65 16 52 H -0.26 -0.54 6.89 56.52 0.39 -0.15 16 LS Contribution 399.08 15.07 6.01 6.01 Total: 0.00 -10.17 399.08 -9.84 -20.01 By element: Atomic # 1 Polarization: -6.50 SS G_CDS: -7.43 Total: -13.92 kcal Atomic # 6 Polarization: 0.71 SS G_CDS: -1.92 Total: -1.21 kcal Atomic # 7 Polarization: -1.30 SS G_CDS: -0.51 Total: -1.82 kcal Atomic # 8 Polarization: -2.80 SS G_CDS: -0.71 Total: -3.51 kcal Atomic # 9 Polarization: 0.00 SS G_CDS: 0.03 Total: 0.03 kcal Atomic # 14 Polarization: -0.28 SS G_CDS: -5.31 Total: -5.59 kcal Total LS contribution 6.01 Total: 6.01 kcal Total: -10.17 -9.84 -20.01 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_22_16500644_12360566.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 -63.835 kcal (2) G-P(sol) polarization free energy of solvation -10.173 kcal (3) G-ENP(sol) elect.-nuc.-pol. free energy of system -74.008 kcal (4) G-CDS(sol) cavity-dispersion-solvent structure free energy -9.838 kcal (5) G-P-CDS(sol) = G-P(sol) + G-CDS(sol) = (2) + (4) -20.011 kcal (6) G-S(sol) free energy of system = (1) + (5) -83.845 kcal 1SCF WAS SPECIFIED, SO GEOMETRY OPTIMIZATION WAS NOT USED Total computer time = 1.28 seconds