Wall clock time and date at job start Tue Mar 31 2020 20:06:50 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 1.50695 * 109.46961 * 2 1 4 4 C 1.32999 * 120.00084 * 94.99945 * 3 2 1 5 5 C 1.47102 * 119.99894 * 172.65293 * 4 3 2 6 6 O 1.21618 * 120.00152 * 2.78205 * 5 4 3 7 7 N 1.34773 * 120.00079 * 182.78040 * 5 4 3 8 8 C 1.46925 * 120.63337 * 174.73660 * 7 5 4 9 9 C 1.53190 * 108.77690 * 233.58526 * 8 7 5 10 10 C 1.53036 * 109.31239 * 305.36486 * 9 8 7 11 11 O 1.42902 * 109.45886 * 181.38379 * 10 9 8 12 12 C 1.42898 * 113.99842 * 149.97561 * 11 10 9 13 13 C 1.53497 * 114.20805 * 150.00324 * 12 11 10 14 14 N 1.47069 * 87.99002 * 87.51389 * 13 12 11 15 15 C 1.36932 * 136.06206 * 206.86534 * 14 13 12 16 16 H 1.08005 * 119.99950 * 359.97438 * 15 14 13 17 17 C 1.38805 * 120.00325 * 180.02562 * 15 14 13 18 18 N 1.31621 * 119.99899 * 359.97438 * 17 15 14 19 19 Si 1.86797 * 120.00295 * 179.97438 * 17 15 14 20 20 H 1.48496 * 109.47472 * 89.99712 * 19 17 15 21 21 H 1.48499 * 109.47208 * 209.99984 * 19 17 15 22 22 H 1.48499 * 109.46864 * 329.99630 * 19 17 15 23 23 C 1.47074 * 87.88120 * 27.12379 * 14 13 12 24 24 C 1.53048 * 109.52867 * 61.37158 * 10 9 8 25 25 C 1.46930 * 120.62846 * 354.71408 * 7 5 4 26 26 C 1.50703 * 119.99805 * 274.99936 * 3 2 1 27 27 C 1.52996 * 109.46984 * 264.66770 * 26 3 2 28 28 H 1.08999 * 109.47364 * 60.00448 * 1 2 3 29 29 H 1.09007 * 109.47010 * 180.02562 * 1 2 3 30 30 H 1.09006 * 109.47225 * 299.99976 * 1 2 3 31 31 H 1.08995 * 109.46677 * 239.99531 * 2 1 3 32 32 H 1.09002 * 109.47077 * 119.99975 * 2 1 3 33 33 H 1.08002 * 119.99801 * 352.65555 * 4 3 2 34 34 H 1.09002 * 109.58324 * 113.79620 * 8 7 5 35 35 H 1.09000 * 109.70415 * 353.44672 * 8 7 5 36 36 H 1.09000 * 109.49676 * 185.41132 * 9 8 7 37 37 H 1.08999 * 109.49461 * 65.31499 * 9 8 7 38 38 H 1.08997 * 109.46255 * 301.35581 * 10 9 8 39 39 H 1.09001 * 113.28856 * 16.93016 * 12 11 10 40 40 H 1.08999 * 113.46412 * 332.73568 * 13 12 11 41 41 H 1.09002 * 113.52411 * 202.30636 * 13 12 11 42 42 H 0.97004 * 120.00015 * 180.02562 * 18 17 15 43 43 H 1.09000 * 113.46755 * 87.66076 * 23 14 13 44 44 H 1.08993 * 113.46245 * 218.10139 * 23 14 13 45 45 H 1.09002 * 109.49585 * 58.58066 * 24 10 9 46 46 H 1.08996 * 109.49920 * 178.67546 * 24 10 9 47 47 H 1.08999 * 109.58577 * 246.20216 * 25 7 5 48 48 H 1.09002 * 109.58632 * 6.48101 * 25 7 5 49 49 H 1.09000 * 109.47052 * 24.67060 * 26 3 2 50 50 H 1.09000 * 109.46749 * 144.67183 * 26 3 2 51 51 H 1.09001 * 109.47091 * 179.97438 * 27 26 3 52 52 H 1.09000 * 109.47462 * 300.00038 * 27 26 3 53 53 H 1.09000 * 109.47040 * 60.00591 * 27 26 3 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 2.0323 1.4208 0.0000 4 6 2.3486 2.0143 1.1474 5 6 2.9893 3.3384 1.1384 6 8 3.1839 3.9127 0.0841 7 7 3.3608 3.9153 2.2984 8 6 4.1040 5.1826 2.3000 9 6 5.3779 5.0062 3.1325 10 6 5.0051 4.4944 4.5257 11 8 6.1883 4.3594 5.3155 12 6 5.9785 4.5568 6.7152 13 6 6.9348 3.7602 7.6135 14 7 7.8793 4.8833 7.5158 15 6 9.2373 5.0395 7.5970 16 1 9.8697 4.1826 7.7767 17 6 9.8011 6.2993 7.4495 18 7 9.0304 7.3437 7.2311 19 14 11.6535 6.5125 7.5611 20 1 12.2516 6.3594 6.2106 21 1 11.9651 7.8646 8.0901 22 1 12.2162 5.4830 8.4714 23 6 6.7229 5.7657 7.2988 24 6 4.3157 3.1335 4.4033 25 6 3.0297 3.2888 3.5856 26 6 2.1762 2.1691 -1.3002 27 6 3.6181 2.0529 -1.7985 28 1 -0.3634 0.5137 -0.8900 29 1 -0.3633 -1.0277 0.0005 30 1 -0.3634 0.5139 0.8900 31 1 1.8933 -0.5139 -0.8899 32 1 1.8934 -0.5138 0.8900 33 1 2.1351 1.5241 2.0858 34 1 3.4871 5.9674 2.7378 35 1 4.3698 5.4541 1.2783 36 1 5.8898 5.9644 3.2217 37 1 6.0347 4.2863 2.6442 38 1 4.3284 5.2027 5.0037 39 1 4.9306 4.4896 7.0075 40 1 7.3014 2.8434 7.1519 41 1 6.5529 3.6007 8.6219 42 1 9.4244 8.2240 7.1276 43 1 6.2839 6.1411 8.2232 44 1 6.9094 6.5540 6.5696 45 1 4.9827 2.4315 3.9030 46 1 4.0715 2.7587 5.3973 47 1 2.3252 3.9192 4.1282 48 1 2.5843 2.3093 3.4114 49 1 1.5001 1.7429 -2.0414 50 1 1.9292 3.2192 -1.1442 51 1 3.7221 2.5937 -2.7392 52 1 4.2942 2.4790 -1.0573 53 1 3.8651 1.0028 -1.9545 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 ZINC001105701851.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 20:06:50 Heat of formation + Delta-G solvation = -4.514404 kcal Electronic energy + Delta-G solvation = -29763.873341 eV Core-core repulsion = 25831.171375 eV Total energy + Delta-G solvation = -3932.701966 eV No. of doubly occupied orbitals = 65 Molecular weight (most abundant/longest-lived isotopes) = 336.220 amu Computer time = 0.99 seconds Orbital eigenvalues (eV) -40.50504 -38.93728 -37.77317 -36.50226 -35.28241 -32.34278 -32.17654 -31.76170 -31.10561 -29.88252 -27.52749 -25.60231 -24.56164 -24.30252 -23.51146 -23.42396 -22.87694 -21.23957 -19.72727 -19.31705 -18.18026 -17.69597 -16.84021 -16.06540 -15.87714 -15.42881 -15.31361 -14.91036 -14.69816 -14.41248 -14.34366 -14.17058 -13.78557 -13.66263 -13.53728 -13.44251 -13.10509 -12.90075 -12.66746 -12.48725 -12.26857 -12.21985 -12.03716 -11.94179 -11.69918 -11.61240 -11.30332 -11.13747 -11.09961 -10.98238 -10.83733 -10.77116 -10.50662 -10.30138 -10.15146 -9.78648 -9.53261 -9.39169 -9.36042 -8.79191 -8.69006 -8.61825 -6.80875 -5.69248 -3.00578 1.14765 2.88240 3.14233 3.44041 3.48090 3.50064 4.00121 4.25120 4.40383 4.51666 4.55207 4.75970 4.80307 4.87787 4.91685 4.96774 5.09759 5.17683 5.19890 5.23412 5.31662 5.37189 5.41555 5.44377 5.47217 5.48171 5.50310 5.52603 5.54223 5.56618 5.71634 5.72693 5.78293 5.84943 5.88514 5.95995 6.01552 6.17447 6.19831 6.28142 6.31256 6.37069 6.41936 6.52470 6.59049 6.60418 7.01968 7.27604 7.32482 7.60337 7.97232 8.08742 8.11965 9.10724 9.77760 10.71209 11.48599 Molecular weight = 336.22amu Principal moments of inertia in cm(-1) A = 0.020556 B = 0.002152 C = 0.002076 Principal moments of inertia in units of 10**(-40)*gram-cm**2 A = 1361.835049 B =13005.965941 C =13482.208783 Net atomic charges, atomic populations, and dipole contributions calculated with CM2 Atom NO. Type Charge No. of electrons 1 C -0.147 4.147 2 C -0.098 4.098 3 C -0.022 4.022 4 C -0.233 4.233 5 C 0.547 3.453 6 O -0.539 6.539 7 N -0.609 5.609 8 C 0.117 3.883 9 C -0.131 4.131 10 C 0.091 3.909 11 O -0.339 6.339 12 C 0.032 3.968 13 C 0.113 3.887 14 N -0.602 5.602 15 C -0.211 4.211 16 H 0.080 0.920 17 C -0.010 4.010 18 N -0.921 5.921 19 Si 0.912 3.088 20 H -0.288 1.288 21 H -0.291 1.291 22 H -0.282 1.282 23 C 0.136 3.864 24 C -0.157 4.157 25 C 0.109 3.891 26 C -0.101 4.101 27 C -0.133 4.133 28 H 0.057 0.943 29 H 0.060 0.940 30 H 0.057 0.943 31 H 0.078 0.922 32 H 0.075 0.925 33 H 0.128 0.872 34 H 0.068 0.932 35 H 0.096 0.904 36 H 0.086 0.914 37 H 0.073 0.927 38 H 0.059 0.941 39 H 0.061 0.939 40 H 0.045 0.955 41 H 0.042 0.958 42 H 0.252 0.748 43 H 0.031 0.969 44 H 0.077 0.923 45 H 0.074 0.926 46 H 0.077 0.923 47 H 0.070 0.930 48 H 0.088 0.912 49 H 0.057 0.943 50 H 0.103 0.897 51 H 0.053 0.947 52 H 0.065 0.935 53 H 0.042 0.958 For the charges calculated by CM2: Dipole moment (debyes) X Y Z Total from point charges -20.562 -12.740 -13.265 27.587 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 -0.204 4.204 2 C -0.135 4.135 3 C -0.024 4.024 4 C -0.254 4.254 5 C 0.340 3.660 6 O -0.419 6.419 7 N -0.342 5.342 8 C -0.005 4.005 9 C -0.169 4.169 10 C 0.032 3.968 11 O -0.257 6.257 12 C -0.027 4.027 13 C -0.013 4.013 14 N -0.328 5.328 15 C -0.338 4.338 16 H 0.098 0.902 17 C -0.206 4.206 18 N -0.569 5.569 19 Si 0.743 3.257 20 H -0.215 1.215 21 H -0.217 1.217 22 H -0.207 1.207 23 C 0.010 3.990 24 C -0.196 4.196 25 C -0.014 4.014 26 C -0.138 4.138 27 C -0.190 4.190 28 H 0.077 0.923 29 H 0.079 0.921 30 H 0.076 0.924 31 H 0.097 0.903 32 H 0.093 0.907 33 H 0.145 0.855 34 H 0.086 0.914 35 H 0.114 0.886 36 H 0.105 0.895 37 H 0.092 0.908 38 H 0.077 0.923 39 H 0.079 0.921 40 H 0.063 0.937 41 H 0.060 0.940 42 H 0.062 0.938 43 H 0.049 0.951 44 H 0.095 0.905 45 H 0.093 0.907 46 H 0.096 0.904 47 H 0.088 0.912 48 H 0.106 0.894 49 H 0.076 0.924 50 H 0.121 0.879 51 H 0.073 0.927 52 H 0.084 0.916 53 H 0.061 0.939 Dipole moment (debyes) X Y Z Total from point charges -19.929 -12.280 -13.879 27.214 hybrid contribution 0.806 0.170 0.647 1.048 sum -19.123 -12.110 -13.232 26.219 Atomic orbital electron populations 1.21720 0.94203 1.02058 1.02422 1.20778 0.96650 0.92716 1.03390 1.22597 0.89870 0.94677 0.95292 1.22467 1.07440 0.96686 0.98811 1.18528 0.78730 0.85715 0.83069 1.90716 1.55962 1.65281 1.29914 1.48055 1.56160 1.24031 1.05940 1.21590 0.92082 0.84760 1.02096 1.21968 0.97306 1.03352 0.94263 1.21993 0.87983 0.94707 0.92106 1.88055 1.29923 1.91063 1.16631 1.23945 0.96104 1.01134 0.81550 1.22651 0.89892 0.93571 0.95228 1.45381 1.00451 1.03239 1.83735 1.18893 0.79300 0.93549 1.42081 0.90235 1.24768 0.97894 0.95387 1.02578 1.69828 1.33263 0.98465 1.55304 0.86113 0.84930 0.76981 0.77707 1.21541 1.21709 1.20740 1.22577 0.85471 0.94026 0.96944 1.22495 0.96799 0.99600 1.00689 1.21808 0.97050 0.98788 0.83737 1.20954 0.97927 1.02058 0.92845 1.21560 0.95931 1.00226 1.01273 0.92346 0.92111 0.92375 0.90332 0.90662 0.85466 0.91400 0.88579 0.89498 0.90842 0.92279 0.92093 0.93654 0.94038 0.93798 0.95127 0.90509 0.90677 0.90400 0.91210 0.89363 0.92429 0.87918 0.92743 0.91573 0.93915 Number of geometries 1 Number of calculations of the screened coulomb radii 1 The total number of SCF iterations 15. 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 -0.77 9.89 37.16 0.37 -0.40 16 2 C -0.10 -0.60 6.08 -27.88 -0.17 -0.77 16 3 C -0.02 -0.19 4.62 -101.17 -0.47 -0.66 16 4 C -0.23 -2.17 8.93 -37.80 -0.34 -2.51 16 5 C 0.55 6.52 7.39 -12.67 -0.09 6.43 16 6 O -0.54 -7.63 10.68 5.26 0.06 -7.58 16 7 N -0.61 -6.78 2.97 -174.16 -0.52 -7.30 16 8 C 0.12 1.38 6.41 -3.71 -0.02 1.35 16 9 C -0.13 -1.80 5.73 -26.61 -0.15 -1.95 16 10 C 0.09 1.29 2.46 -26.69 -0.07 1.22 16 11 O -0.34 -6.56 10.04 -35.23 -0.35 -6.91 16 12 C 0.03 0.61 4.50 -26.21 -0.12 0.49 16 13 C 0.11 2.39 8.52 -8.50 -0.07 2.32 16 14 N -0.60 -16.14 3.78 -184.77 -0.70 -16.84 16 15 C -0.21 -6.16 10.74 -15.06 -0.16 -6.33 16 16 H 0.08 2.24 7.83 -52.48 -0.41 1.83 16 17 C -0.01 -0.30 5.50 -17.43 -0.10 -0.39 16 18 N -0.92 -28.17 11.51 55.49 0.64 -27.53 16 19 Si 0.91 22.85 29.55 -169.99 -5.02 17.82 16 20 H -0.29 -7.21 7.11 56.52 0.40 -6.81 16 21 H -0.29 -7.29 7.11 56.52 0.40 -6.89 16 22 H -0.28 -6.83 7.11 56.52 0.40 -6.43 16 23 C 0.14 3.27 7.24 -8.50 -0.06 3.21 16 24 C -0.16 -1.76 5.69 -26.61 -0.15 -1.91 16 25 C 0.11 0.98 6.35 -3.71 -0.02 0.96 16 26 C -0.10 -0.96 5.35 -27.88 -0.15 -1.11 16 27 C -0.13 -1.34 9.34 37.16 0.35 -0.99 16 28 H 0.06 0.31 8.14 -51.93 -0.42 -0.11 16 29 H 0.06 0.25 8.14 -51.93 -0.42 -0.17 16 30 H 0.06 0.31 8.14 -51.93 -0.42 -0.11 16 31 H 0.08 0.44 8.14 -51.93 -0.42 0.02 16 32 H 0.07 0.42 8.04 -51.93 -0.42 0.00 16 33 H 0.13 0.92 5.85 -52.49 -0.31 0.61 16 34 H 0.07 0.72 8.14 -51.93 -0.42 0.30 16 35 H 0.10 1.21 7.04 -51.93 -0.37 0.84 16 36 H 0.09 1.28 8.14 -51.93 -0.42 0.86 16 37 H 0.07 1.10 8.14 -51.93 -0.42 0.68 16 38 H 0.06 0.79 7.71 -51.93 -0.40 0.39 16 39 H 0.06 0.94 7.76 -51.93 -0.40 0.54 16 40 H 0.05 0.94 8.14 -51.93 -0.42 0.52 16 41 H 0.04 0.81 8.14 -51.93 -0.42 0.38 16 42 H 0.25 7.45 8.31 -40.82 -0.34 7.11 16 43 H 0.03 0.73 8.14 -51.93 -0.42 0.31 16 44 H 0.08 2.08 7.12 -51.93 -0.37 1.71 16 45 H 0.07 0.93 8.14 -51.93 -0.42 0.51 16 46 H 0.08 0.80 8.14 -51.93 -0.42 0.38 16 47 H 0.07 0.55 8.14 -51.93 -0.42 0.13 16 48 H 0.09 0.62 5.30 -51.93 -0.28 0.34 16 49 H 0.06 0.45 8.09 -51.93 -0.42 0.03 16 50 H 0.10 1.19 5.85 -51.93 -0.30 0.89 16 51 H 0.05 0.52 8.14 -51.93 -0.42 0.10 16 52 H 0.07 0.82 6.38 -51.93 -0.33 0.49 16 53 H 0.04 0.37 8.14 -51.93 -0.42 -0.05 16 LS Contribution 412.03 15.07 6.21 6.21 Total: -1.00 -34.17 412.03 -10.60 -44.77 By element: Atomic # 1 Polarization: 7.87 SS G_CDS: -9.48 Total: -1.61 kcal Atomic # 6 Polarization: 0.39 SS G_CDS: -1.43 Total: -1.04 kcal Atomic # 7 Polarization: -51.09 SS G_CDS: -0.58 Total: -51.67 kcal Atomic # 8 Polarization: -14.19 SS G_CDS: -0.30 Total: -14.49 kcal Atomic # 14 Polarization: 22.85 SS G_CDS: -5.02 Total: 17.82 kcal Total LS contribution 6.21 Total: 6.21 kcal Total: -34.17 -10.60 -44.77 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. ZINC001105701851.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 40.259 kcal (2) G-P(sol) polarization free energy of solvation -34.173 kcal (3) G-ENP(sol) elect.-nuc.-pol. free energy of system 6.086 kcal (4) G-CDS(sol) cavity-dispersion-solvent structure free energy -10.600 kcal (5) G-P-CDS(sol) = G-P(sol) + G-CDS(sol) = (2) + (4) -44.773 kcal (6) G-S(sol) free energy of system = (1) + (5) -4.514 kcal 1SCF WAS SPECIFIED, SO GEOMETRY OPTIMIZATION WAS NOT USED Total computer time = 0.99 seconds