Wall clock time and date at job start Tue Mar 31 2020 20:48:06 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 1.31003 * 1 3 3 C 1.50702 * 120.00136 * 2 1 4 4 N 1.46504 * 109.46822 * 125.74800 * 3 2 1 5 5 C 1.46497 * 120.00208 * 86.23806 * 4 3 2 6 6 C 1.50701 * 109.47133 * 92.14886 * 5 4 3 7 7 H 1.07999 * 119.99792 * 359.97438 * 6 5 4 8 8 C 1.37871 * 120.00177 * 179.97438 * 6 5 4 9 9 N 1.31518 * 119.99857 * 0.02562 * 8 6 5 10 10 Si 1.86804 * 120.00102 * 180.02562 * 8 6 5 11 11 H 1.48497 * 109.46846 * 359.97438 * 10 8 6 12 12 H 1.48497 * 109.47161 * 120.00065 * 10 8 6 13 13 H 1.48503 * 109.46888 * 240.00284 * 10 8 6 14 14 C 1.34776 * 119.99836 * 266.24022 * 4 3 2 15 15 O 1.21283 * 120.00057 * 356.04398 * 14 4 3 16 16 C 1.50697 * 120.00040 * 176.05224 * 14 4 3 17 17 H 1.08997 * 109.47015 * 327.43558 * 16 14 4 18 18 C 1.53006 * 109.47119 * 87.43546 * 16 14 4 19 19 N 1.46501 * 109.47505 * 207.43422 * 16 14 4 20 20 C 1.34768 * 120.00257 * 155.00039 * 19 16 14 21 21 O 1.21283 * 119.99943 * 359.97438 * 20 19 16 22 22 C 1.50697 * 120.00172 * 180.02562 * 20 19 16 23 23 C 1.53000 * 109.47566 * 179.97438 * 22 20 19 24 24 C 1.53006 * 109.47032 * 295.00168 * 23 22 20 25 25 C 1.53003 * 109.46986 * 179.97438 * 24 23 22 26 26 C 1.53005 * 109.46938 * 60.00189 * 25 24 23 27 27 C 1.53002 * 109.46624 * 299.99633 * 26 25 24 28 28 C 1.52997 * 109.47398 * 60.00648 * 27 26 25 29 29 H 1.08005 * 119.99391 * 5.08827 * 1 2 3 30 30 H 1.07992 * 120.00298 * 185.09003 * 1 2 3 31 31 H 1.08000 * 119.99722 * 180.02562 * 2 1 3 32 32 H 1.09001 * 109.47143 * 5.75083 * 3 2 1 33 33 H 1.08994 * 109.47069 * 245.74141 * 3 2 1 34 34 H 1.09000 * 109.47361 * 212.15036 * 5 4 3 35 35 H 1.09005 * 109.47080 * 332.15262 * 5 4 3 36 36 H 0.97000 * 120.00019 * 180.02562 * 9 8 6 37 37 H 1.09004 * 109.47149 * 186.37531 * 18 16 14 38 38 H 1.09000 * 109.46712 * 306.37351 * 18 16 14 39 39 H 1.08999 * 109.47059 * 66.37130 * 18 16 14 40 40 H 0.97004 * 119.99841 * 335.00089 * 19 16 14 41 41 H 1.09005 * 109.47255 * 300.00073 * 22 20 19 42 42 H 1.09006 * 109.47196 * 59.99434 * 22 20 19 43 43 H 1.09000 * 109.46925 * 54.99456 * 23 22 20 44 44 H 1.09002 * 109.46842 * 299.99952 * 24 23 22 45 45 H 1.09002 * 109.47110 * 59.99547 * 24 23 22 46 46 H 1.08993 * 109.46819 * 299.99986 * 25 24 23 47 47 H 1.08997 * 109.46470 * 179.97438 * 25 24 23 48 48 H 1.09003 * 109.46710 * 179.97438 * 26 25 24 49 49 H 1.08993 * 109.47103 * 59.99589 * 26 25 24 50 50 H 1.08993 * 109.47345 * 299.99808 * 27 26 25 51 51 H 1.09002 * 109.46606 * 180.02562 * 27 26 25 52 52 H 1.08994 * 109.47361 * 179.97438 * 28 27 26 53 53 H 1.09005 * 109.47192 * 59.99157 * 28 27 26 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 1.3100 0.0000 0.0000 3 6 2.0636 1.3051 0.0000 4 7 3.0066 1.3244 1.1210 5 6 4.3426 0.7443 0.9645 6 6 5.3068 1.8153 0.5235 7 1 4.9590 2.8268 0.3744 8 6 6.6329 1.5038 0.3105 9 7 7.0563 0.2719 0.4917 10 14 7.8282 2.8316 -0.2354 11 1 7.1070 4.1230 -0.3671 12 1 8.9099 2.9686 0.7726 13 1 8.4175 2.4584 -1.5464 14 6 2.6449 1.8759 2.2964 15 8 1.5662 2.4198 2.4046 16 6 3.5807 1.8170 3.4761 17 1 4.1589 0.8939 3.4354 18 6 4.5304 3.0160 3.4341 19 7 2.8042 1.8525 4.7178 20 6 3.3148 1.3234 5.8473 21 8 4.4170 0.8175 5.8356 22 6 2.5158 1.3594 7.1245 23 6 3.3177 0.6972 8.2467 24 6 3.5079 -0.7876 7.9299 25 6 4.3104 -1.4496 9.0519 26 6 3.5549 -1.3030 10.3743 27 6 3.3647 0.1818 10.6909 28 6 2.5622 0.8438 9.5691 29 1 -0.5399 0.9317 -0.0830 30 1 -0.5400 -0.9315 0.0830 31 1 1.8500 -0.9353 -0.0004 32 1 1.3598 2.1310 0.1030 33 1 2.6109 1.4086 -0.9369 34 1 4.6721 0.3285 1.9167 35 1 4.3099 -0.0462 0.2147 36 1 7.9893 0.0529 0.3422 37 1 5.2787 2.9145 4.2202 38 1 5.0256 3.0533 2.4638 39 1 3.9635 3.9341 3.5883 40 1 1.9225 2.2568 4.7271 41 1 2.3035 2.3947 7.3913 42 1 1.5784 0.8215 6.9820 43 1 4.2920 1.1786 8.3298 44 1 2.5335 -1.2691 7.8467 45 1 4.0464 -0.8921 6.9880 46 1 5.2846 -0.9680 9.1346 47 1 4.4455 -2.5074 8.8264 48 1 4.1264 -1.7751 11.1735 49 1 2.5806 -1.7845 10.2914 50 1 4.3390 0.6633 10.7738 51 1 2.8269 0.2863 11.6332 52 1 2.4264 1.9014 9.7949 53 1 1.5879 0.3622 9.4862 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 ZINC000292529781.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 20:48:06 Heat of formation + Delta-G solvation = -85.145122 kcal Electronic energy + Delta-G solvation = -30269.484009 eV Core-core repulsion = 26333.285632 eV Total energy + Delta-G solvation = -3936.198377 eV No. of doubly occupied orbitals = 65 Molecular weight (most abundant/longest-lived isotopes) = 336.220 amu Computer time = 0.79 seconds Orbital eigenvalues (eV) -40.16678 -39.24160 -37.98050 -35.67378 -34.59157 -33.49228 -32.75751 -32.21992 -30.74999 -30.26180 -27.53196 -27.00512 -26.05992 -23.43271 -23.01133 -22.65480 -21.60926 -20.03363 -19.74899 -19.61848 -18.61415 -17.18214 -16.59867 -16.25465 -15.88998 -15.35493 -15.28522 -15.04493 -14.68103 -14.37292 -14.21993 -14.19071 -13.92943 -13.79819 -13.32665 -13.05454 -12.87503 -12.50188 -12.43690 -12.26621 -12.04266 -11.92154 -11.76136 -11.63417 -11.49851 -11.34354 -11.18048 -11.12104 -11.01621 -10.98181 -10.83638 -10.71905 -10.48955 -10.28264 -10.14944 -10.07685 -9.78483 -9.38763 -9.33243 -9.02897 -8.67905 -8.57284 -7.86261 -6.22136 -4.29345 2.46772 2.90506 3.15023 3.20501 3.29658 3.31831 3.41374 4.04851 4.30463 4.57575 4.65662 4.67398 4.97287 5.04820 5.11078 5.17010 5.18859 5.27709 5.31753 5.43242 5.44148 5.50222 5.51958 5.56099 5.61053 5.67871 5.74294 5.80531 5.84077 5.89011 5.95906 6.05768 6.10327 6.12953 6.15679 6.24319 6.27138 6.32093 6.38733 6.48323 6.53164 6.61947 6.73968 6.86668 6.98115 7.04637 7.15017 7.40828 7.71049 7.82436 7.98779 8.17977 8.53280 8.70163 8.85059 9.37405 10.84706 Molecular weight = 336.22amu Principal moments of inertia in cm(-1) A = 0.010408 B = 0.003134 C = 0.002684 Principal moments of inertia in units of 10**(-40)*gram-cm**2 A = 2689.595580 B = 8932.713547 C =10428.729640 Net atomic charges, atomic populations, and dipole contributions calculated with CM2 Atom NO. Type Charge No. of electrons 1 C -0.190 4.190 2 C -0.159 4.159 3 C 0.141 3.859 4 N -0.585 5.585 5 C 0.232 3.768 6 C -0.539 4.539 7 H 0.064 0.936 8 C 0.068 3.932 9 N -0.885 5.885 10 Si 0.894 3.106 11 H -0.271 1.271 12 H -0.281 1.281 13 H -0.282 1.282 14 C 0.518 3.482 15 O -0.574 6.574 16 C 0.132 3.868 17 H 0.115 0.885 18 C -0.161 4.161 19 N -0.717 5.717 20 C 0.511 3.489 21 O -0.533 6.533 22 C -0.136 4.136 23 C -0.070 4.070 24 C -0.121 4.121 25 C -0.118 4.118 26 C -0.120 4.120 27 C -0.118 4.118 28 C -0.115 4.115 29 H 0.095 0.905 30 H 0.093 0.907 31 H 0.108 0.892 32 H 0.080 0.920 33 H 0.086 0.914 34 H 0.042 0.958 35 H 0.039 0.961 36 H 0.266 0.734 37 H 0.062 0.938 38 H 0.105 0.895 39 H 0.048 0.952 40 H 0.403 0.597 41 H 0.091 0.909 42 H 0.090 0.910 43 H 0.078 0.922 44 H 0.053 0.947 45 H 0.085 0.915 46 H 0.062 0.938 47 H 0.058 0.942 48 H 0.057 0.943 49 H 0.059 0.941 50 H 0.061 0.939 51 H 0.058 0.942 52 H 0.060 0.940 53 H 0.061 0.939 For the charges calculated by CM2: Dipole moment (debyes) X Y Z Total from point charges -9.731 -0.612 13.524 16.672 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 -0.228 4.228 2 C -0.178 4.178 3 C 0.018 3.982 4 N -0.314 5.314 5 C 0.112 3.888 6 C -0.578 4.578 7 H 0.082 0.918 8 C -0.136 4.136 9 N -0.522 5.522 10 Si 0.721 3.279 11 H -0.196 1.196 12 H -0.207 1.207 13 H -0.208 1.208 14 C 0.305 3.695 15 O -0.455 6.455 16 C 0.025 3.975 17 H 0.133 0.867 18 C -0.220 4.220 19 N -0.370 5.370 20 C 0.297 3.703 21 O -0.410 6.410 22 C -0.176 4.176 23 C -0.089 4.089 24 C -0.159 4.159 25 C -0.155 4.155 26 C -0.157 4.157 27 C -0.156 4.156 28 C -0.152 4.152 29 H 0.113 0.887 30 H 0.111 0.889 31 H 0.126 0.874 32 H 0.099 0.901 33 H 0.104 0.896 34 H 0.060 0.940 35 H 0.057 0.943 36 H 0.076 0.924 37 H 0.081 0.919 38 H 0.124 0.876 39 H 0.067 0.933 40 H 0.239 0.761 41 H 0.109 0.891 42 H 0.109 0.891 43 H 0.097 0.903 44 H 0.071 0.929 45 H 0.104 0.896 46 H 0.080 0.920 47 H 0.077 0.923 48 H 0.075 0.925 49 H 0.077 0.923 50 H 0.080 0.920 51 H 0.077 0.923 52 H 0.079 0.921 53 H 0.080 0.920 Dipole moment (debyes) X Y Z Total from point charges -9.291 -0.831 13.519 16.425 hybrid contribution 0.379 0.735 -0.459 0.946 sum -8.911 -0.096 13.060 15.811 Atomic orbital electron populations 1.23737 0.95825 1.01447 1.01747 1.23418 0.96129 0.99468 0.98778 1.20404 0.92276 0.94934 0.90545 1.48152 1.16269 1.56671 1.10325 1.19584 0.76203 0.94420 0.98570 1.21423 0.93238 0.95799 1.47322 0.91761 1.24931 0.98184 0.95571 0.94896 1.69925 1.16522 1.17982 1.47788 0.86499 0.81062 0.81870 0.78456 1.19562 1.20673 1.20831 1.20427 0.86543 0.77853 0.84679 1.90566 1.24553 1.46055 1.84356 1.20797 0.91845 1.03089 0.81813 0.86731 1.22213 0.98641 0.95163 1.05942 1.45984 1.21510 1.60739 1.08773 1.20643 0.87095 0.77628 0.84947 1.90699 1.20495 1.44393 1.85412 1.21746 0.99808 1.03081 0.93003 1.20902 0.99082 0.96538 0.92345 1.21724 1.00133 0.94089 0.99919 1.21501 0.99138 1.00350 0.94517 1.21556 1.00396 0.96267 0.97514 1.21506 1.00378 0.95902 0.97774 1.21600 0.98846 1.00323 0.94446 0.88684 0.88907 0.87393 0.90141 0.89556 0.94049 0.94308 0.92428 0.91901 0.87646 0.93292 0.76089 0.89065 0.89118 0.90317 0.92851 0.89629 0.91962 0.92297 0.92467 0.92266 0.92005 0.92333 0.92099 0.92030 Number of geometries 1 Number of calculations of the screened coulomb radii 1 The total number of SCF iterations 12. 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 -0.19 -2.66 14.31 29.01 0.42 -2.25 16 2 C -0.16 -2.54 9.85 -36.03 -0.35 -2.90 16 3 C 0.14 2.54 5.91 -5.19 -0.03 2.51 16 4 N -0.59 -11.95 2.44 -176.43 -0.43 -12.38 16 5 C 0.23 5.34 5.00 -5.20 -0.03 5.32 16 6 C -0.54 -13.40 7.16 -34.44 -0.25 -13.64 16 7 H 0.06 1.61 7.47 -52.49 -0.39 1.22 16 8 C 0.07 1.76 5.46 -17.82 -0.10 1.66 16 9 N -0.88 -24.02 13.29 55.43 0.74 -23.29 16 10 Si 0.89 20.16 29.54 -169.99 -5.02 15.14 16 11 H -0.27 -6.04 7.11 56.52 0.40 -5.64 16 12 H -0.28 -6.37 7.11 56.52 0.40 -5.97 16 13 H -0.28 -6.36 7.11 56.52 0.40 -5.96 16 14 C 0.52 10.47 6.85 -10.99 -0.08 10.39 16 15 O -0.57 -12.05 15.55 5.56 0.09 -11.96 16 16 C 0.13 2.52 2.29 -69.08 -0.16 2.36 16 17 H 0.12 2.46 5.49 -51.93 -0.29 2.17 16 18 C -0.16 -3.07 9.45 37.16 0.35 -2.72 16 19 N -0.72 -11.48 5.06 -54.93 -0.28 -11.75 16 20 C 0.51 7.87 7.51 -10.99 -0.08 7.79 16 21 O -0.53 -10.13 13.63 5.55 0.08 -10.06 16 22 C -0.14 -1.50 5.18 -27.88 -0.14 -1.64 16 23 C -0.07 -0.77 1.84 -90.62 -0.17 -0.94 16 24 C -0.12 -1.46 4.94 -26.73 -0.13 -1.59 16 25 C -0.12 -1.25 5.92 -26.73 -0.16 -1.41 16 26 C -0.12 -1.06 5.92 -26.73 -0.16 -1.22 16 27 C -0.12 -1.00 5.92 -26.73 -0.16 -1.16 16 28 C -0.11 -1.00 5.21 -26.73 -0.14 -1.14 16 29 H 0.09 1.28 7.86 -52.48 -0.41 0.87 16 30 H 0.09 1.13 8.06 -52.49 -0.42 0.71 16 31 H 0.11 1.73 8.06 -52.49 -0.42 1.30 16 32 H 0.08 1.44 6.93 -51.93 -0.36 1.08 16 33 H 0.09 1.52 8.10 -51.93 -0.42 1.10 16 34 H 0.04 1.02 5.86 -51.93 -0.30 0.71 16 35 H 0.04 0.94 8.06 -51.93 -0.42 0.52 16 36 H 0.27 6.90 8.31 -40.82 -0.34 6.56 16 37 H 0.06 1.19 8.14 -51.93 -0.42 0.77 16 38 H 0.11 2.23 5.27 -51.93 -0.27 1.96 16 39 H 0.05 0.85 8.14 -51.93 -0.42 0.43 16 40 H 0.40 5.87 7.81 -40.82 -0.32 5.55 16 41 H 0.09 0.83 8.14 -51.93 -0.42 0.41 16 42 H 0.09 0.87 8.14 -51.93 -0.42 0.44 16 43 H 0.08 1.00 7.96 -51.93 -0.41 0.59 16 44 H 0.05 0.60 8.14 -51.93 -0.42 0.17 16 45 H 0.09 1.29 5.95 -51.93 -0.31 0.99 16 46 H 0.06 0.70 8.14 -51.93 -0.42 0.28 16 47 H 0.06 0.61 8.14 -51.93 -0.42 0.18 16 48 H 0.06 0.46 8.14 -51.93 -0.42 0.04 16 49 H 0.06 0.51 8.14 -51.93 -0.42 0.08 16 50 H 0.06 0.54 8.14 -51.93 -0.42 0.12 16 51 H 0.06 0.43 8.14 -51.93 -0.42 0.01 16 52 H 0.06 0.48 8.14 -51.93 -0.42 0.06 16 53 H 0.06 0.51 8.14 -51.93 -0.42 0.08 16 LS Contribution 416.57 15.07 6.28 6.28 Total: -1.00 -28.45 416.57 -9.30 -37.75 By element: Atomic # 1 Polarization: 20.23 SS G_CDS: -9.38 Total: 10.85 kcal Atomic # 6 Polarization: 0.79 SS G_CDS: -1.36 Total: -0.57 kcal Atomic # 7 Polarization: -47.45 SS G_CDS: 0.03 Total: -47.42 kcal Atomic # 8 Polarization: -22.18 SS G_CDS: 0.16 Total: -22.02 kcal Atomic # 14 Polarization: 20.16 SS G_CDS: -5.02 Total: 15.14 kcal Total LS contribution 6.28 Total: 6.28 kcal Total: -28.45 -9.30 -37.75 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. ZINC000292529781.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 -47.391 kcal (2) G-P(sol) polarization free energy of solvation -28.455 kcal (3) G-ENP(sol) elect.-nuc.-pol. free energy of system -75.845 kcal (4) G-CDS(sol) cavity-dispersion-solvent structure free energy -9.300 kcal (5) G-P-CDS(sol) = G-P(sol) + G-CDS(sol) = (2) + (4) -37.754 kcal (6) G-S(sol) free energy of system = (1) + (5) -85.145 kcal 1SCF WAS SPECIFIED, SO GEOMETRY OPTIMIZATION WAS NOT USED Total computer time = 0.79 seconds