Wall clock time and date at job start Sat Apr 11 2020 06:10:59 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 1.52999 * 1 3 3 N 1.46498 * 109.47089 * 2 1 4 4 C 1.46509 * 119.99756 * 270.00039 * 3 2 1 5 5 C 1.50697 * 109.47094 * 269.99893 * 4 3 2 6 6 H 1.08008 * 120.00166 * 0.02562 * 5 4 3 7 7 C 1.37875 * 120.00193 * 180.02562 * 5 4 3 8 8 N 1.31512 * 119.99676 * 0.02562 * 7 5 4 9 9 Si 1.86805 * 120.00140 * 180.02562 * 7 5 4 10 10 H 1.48495 * 109.46865 * 60.00063 * 9 7 5 11 11 H 1.48498 * 109.47046 * 180.02562 * 9 7 5 12 12 H 1.48498 * 109.46940 * 299.99636 * 9 7 5 13 13 C 1.34773 * 120.00316 * 89.99881 * 3 2 1 14 14 O 1.21275 * 120.00278 * 179.97438 * 13 3 2 15 15 C 1.50706 * 119.99516 * 0.02562 * 13 3 2 16 16 N 1.46903 * 109.46671 * 185.61093 * 15 13 3 17 17 C 1.46901 * 110.99550 * 208.95708 * 16 15 13 18 18 C 1.53003 * 109.46776 * 152.33394 * 17 16 15 19 19 C 1.52998 * 117.49630 * 243.78973 * 18 17 16 20 20 C 1.53002 * 117.49965 * 175.13149 * 18 17 16 21 21 C 1.46903 * 110.99679 * 85.00651 * 16 15 13 22 22 C 1.52995 * 109.47411 * 312.12947 * 21 16 15 23 23 C 1.53004 * 109.46809 * 192.13084 * 21 16 15 24 24 C 1.52999 * 109.47204 * 56.38503 * 23 21 16 25 25 C 1.50700 * 109.47237 * 72.13000 * 21 16 15 26 26 O 1.20831 * 119.99826 * 146.71124 * 25 21 16 27 27 O 1.34224 * 120.00025 * 326.71152 * 25 21 16 28 28 H 1.08995 * 109.47260 * 299.99746 * 1 2 3 29 29 H 1.09007 * 109.47094 * 60.00169 * 1 2 3 30 30 H 1.08997 * 109.46952 * 179.97438 * 1 2 3 31 31 H 1.09008 * 109.47166 * 239.99944 * 2 1 3 32 32 H 1.08996 * 109.47517 * 120.00111 * 2 1 3 33 33 H 1.08995 * 109.47394 * 30.00117 * 4 3 2 34 34 H 1.08998 * 109.46933 * 150.00084 * 4 3 2 35 35 H 0.97001 * 119.99849 * 180.02562 * 8 7 5 36 36 H 1.08994 * 109.47137 * 65.61080 * 15 13 3 37 37 H 1.09000 * 109.46856 * 305.61090 * 15 13 3 38 38 H 1.08999 * 109.46923 * 272.32751 * 17 16 15 39 39 H 1.08995 * 109.47381 * 32.33061 * 17 16 15 40 40 H 1.08998 * 115.55188 * 29.45559 * 18 17 16 41 41 H 1.09007 * 117.50076 * 0.02562 * 19 18 17 42 42 H 1.09003 * 117.49893 * 145.01779 * 19 18 17 43 43 H 1.08996 * 117.50171 * 214.98107 * 20 18 17 44 44 H 1.09004 * 117.49560 * 359.97438 * 20 18 17 45 45 H 1.09000 * 109.47445 * 176.09027 * 22 21 16 46 46 H 1.09002 * 109.46896 * 296.09051 * 22 21 16 47 47 H 1.08994 * 109.47138 * 56.08768 * 22 21 16 48 48 H 1.08995 * 109.46981 * 176.38852 * 23 21 16 49 49 H 1.08998 * 109.46831 * 296.38186 * 23 21 16 50 50 H 1.08998 * 109.46681 * 65.74153 * 24 23 21 51 51 H 1.08999 * 109.47177 * 185.74175 * 24 23 21 52 52 H 1.08997 * 109.46848 * 305.74330 * 24 23 21 53 53 H 0.96706 * 116.99989 * 174.99311 * 27 25 21 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 7 2.0183 1.3812 0.0000 4 6 2.2625 2.0718 -1.2688 5 6 3.6857 1.8350 -1.7039 6 1 4.3426 1.2302 -1.0962 7 6 4.1493 2.3904 -2.8775 8 7 3.3496 3.1273 -3.6171 9 14 5.9134 2.0963 -3.4171 10 1 6.1401 0.6396 -3.5955 11 1 6.1613 2.7974 -4.7025 12 1 6.8412 2.6187 -2.3821 13 6 2.2429 2.0166 1.1671 14 8 2.6476 3.1598 1.1671 15 6 1.9923 1.3059 2.4723 16 7 2.1807 2.2457 3.5855 17 6 2.6240 1.5439 4.7975 18 6 3.4439 2.4981 5.6682 19 6 4.9164 2.1536 5.9005 20 6 3.9030 1.9884 7.0359 21 6 0.9541 3.0128 3.8402 22 6 0.4114 3.5606 2.5188 23 6 1.2666 4.1756 4.7843 24 6 2.3783 5.0370 4.1820 25 6 -0.0776 2.1150 4.4732 26 8 -0.8576 2.5652 5.2787 27 8 -0.1299 0.8153 4.1422 28 1 -0.3633 0.5138 0.8900 29 1 -0.3634 0.5138 -0.8901 30 1 -0.3633 -1.0276 -0.0005 31 1 1.8934 -0.5139 -0.8900 32 1 1.8934 -0.5138 0.8899 33 1 1.5817 1.6877 -2.0285 34 1 2.0955 3.1410 -1.1385 35 1 3.6756 3.5177 -4.4431 36 1 2.6919 0.4765 2.5745 37 1 0.9714 0.9242 2.4878 38 1 1.7540 1.1990 5.3563 39 1 3.2387 0.6884 4.5177 40 1 3.1806 3.5527 5.5866 41 1 5.3011 1.2473 5.4327 42 1 5.6218 2.9815 5.9721 43 1 3.9421 2.7077 7.8539 44 1 3.6206 0.9734 7.3154 45 1 -0.5351 4.0706 2.6981 46 1 1.1285 4.2639 2.0952 47 1 0.2543 2.7377 1.8215 48 1 0.3715 4.7820 4.9225 49 1 1.5922 3.7837 5.7479 50 1 2.0167 5.5108 3.2694 51 1 2.6716 5.8046 4.8982 52 1 3.2385 4.4094 3.9493 53 1 -0.7581 0.2635 4.6280 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 ZINC001596299739.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 06:10:59 Heat of formation + Delta-G solvation = -74.566810 kcal Electronic energy + Delta-G solvation = -33191.975315 eV Core-core repulsion = 29065.779597 eV Total energy + Delta-G solvation = -4126.195718 eV No. of doubly occupied orbitals = 66 Molecular weight (most abundant/longest-lived isotopes) = 340.220 amu Computer time = 0.90 seconds Orbital eigenvalues (eV) -41.36424 -39.22628 -38.16497 -36.53551 -36.33129 -35.08576 -33.34071 -32.70552 -30.16057 -29.90822 -28.67122 -26.68430 -25.53845 -24.27309 -23.01287 -22.95164 -22.41947 -22.17200 -20.82076 -19.29693 -18.32952 -18.26275 -17.00248 -16.62459 -16.42330 -16.03894 -15.66986 -15.58527 -15.15745 -14.83410 -14.42574 -14.10047 -13.79869 -13.70016 -13.47968 -13.32470 -13.03511 -12.85518 -12.46795 -12.26545 -12.05281 -11.98567 -11.96153 -11.71507 -11.65493 -11.55830 -11.47060 -11.40006 -11.17969 -11.08317 -10.93402 -10.88434 -10.74323 -10.61433 -10.48062 -10.47410 -10.16667 -10.08454 -9.92595 -9.57977 -8.87169 -8.39633 -8.24254 -7.55790 -6.00642 -4.04841 2.02121 2.81103 3.33881 3.38506 3.39761 3.43765 3.53448 3.81003 4.20274 4.48780 4.57229 4.65296 4.71939 4.87198 4.95217 5.02792 5.14197 5.29852 5.33373 5.34713 5.41886 5.44565 5.48847 5.52340 5.54746 5.62259 5.66115 5.70123 5.72212 5.80714 5.84819 5.88551 5.97676 6.03865 6.05731 6.07915 6.17921 6.25479 6.26903 6.31556 6.49646 6.57753 6.73895 6.82204 6.94138 7.17093 7.49559 7.63083 7.71505 7.96713 8.28586 8.51994 8.95846 9.23449 9.60473 11.07203 Molecular weight = 340.22amu Principal moments of inertia in cm(-1) A = 0.012227 B = 0.003853 C = 0.003444 Principal moments of inertia in units of 10**(-40)*gram-cm**2 A = 2289.423188 B = 7266.066109 C = 8127.511215 Net atomic charges, atomic populations, and dipole contributions calculated with CM2 Atom NO. Type Charge No. of electrons 1 C -0.169 4.169 2 C 0.108 3.892 3 N -0.602 5.602 4 C 0.250 3.750 5 C -0.523 4.523 6 H 0.056 0.944 7 C 0.062 3.938 8 N -0.896 5.896 9 Si 0.896 3.104 10 H -0.278 1.278 11 H -0.287 1.287 12 H -0.276 1.276 13 C 0.507 3.493 14 O -0.517 6.517 15 C 0.025 3.975 16 N -0.487 5.487 17 C 0.085 3.915 18 C -0.162 4.162 19 C -0.172 4.172 20 C -0.187 4.187 21 C 0.135 3.865 22 C -0.152 4.152 23 C -0.104 4.104 24 C -0.150 4.150 25 C 0.456 3.544 26 O -0.515 6.515 27 O -0.514 6.514 28 H 0.049 0.951 29 H 0.060 0.940 30 H 0.058 0.942 31 H 0.081 0.919 32 H 0.061 0.939 33 H 0.029 0.971 34 H 0.043 0.957 35 H 0.263 0.737 36 H 0.093 0.907 37 H 0.087 0.913 38 H 0.042 0.958 39 H 0.078 0.922 40 H 0.132 0.868 41 H 0.092 0.908 42 H 0.093 0.907 43 H 0.092 0.908 44 H 0.089 0.911 45 H 0.057 0.943 46 H 0.114 0.886 47 H 0.063 0.937 48 H 0.073 0.927 49 H 0.073 0.927 50 H 0.062 0.938 51 H 0.047 0.953 52 H 0.085 0.915 53 H 0.398 0.602 For the charges calculated by CM2: Dipole moment (debyes) X Y Z Total from point charges -5.608 -5.759 18.363 20.045 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 -0.227 4.227 2 C -0.017 4.017 3 N -0.335 5.335 4 C 0.131 3.869 5 C -0.562 4.562 6 H 0.074 0.926 7 C -0.140 4.140 8 N -0.535 5.535 9 Si 0.724 3.276 10 H -0.204 1.204 11 H -0.213 1.213 12 H -0.202 1.202 13 C 0.293 3.707 14 O -0.392 6.392 15 C -0.105 4.105 16 N -0.211 5.211 17 C -0.043 4.043 18 C -0.180 4.180 19 C -0.209 4.209 20 C -0.224 4.224 21 C 0.043 3.957 22 C -0.208 4.208 23 C -0.142 4.142 24 C -0.206 4.206 25 C 0.296 3.704 26 O -0.402 6.402 27 O -0.327 6.327 28 H 0.068 0.932 29 H 0.079 0.921 30 H 0.077 0.923 31 H 0.099 0.901 32 H 0.080 0.920 33 H 0.047 0.953 34 H 0.061 0.939 35 H 0.072 0.928 36 H 0.111 0.889 37 H 0.105 0.895 38 H 0.059 0.941 39 H 0.097 0.903 40 H 0.149 0.851 41 H 0.111 0.889 42 H 0.111 0.889 43 H 0.110 0.890 44 H 0.107 0.893 45 H 0.076 0.924 46 H 0.132 0.868 47 H 0.082 0.918 48 H 0.091 0.909 49 H 0.092 0.908 50 H 0.081 0.919 51 H 0.066 0.934 52 H 0.104 0.896 53 H 0.258 0.742 Dipole moment (debyes) X Y Z Total from point charges -4.977 -4.324 18.020 19.188 hybrid contribution -0.168 -1.384 0.153 1.402 sum -5.144 -5.707 18.173 19.730 Atomic orbital electron populations 1.22225 0.97021 1.01306 1.02167 1.21369 0.93330 0.84555 1.02437 1.48258 1.64480 1.13118 1.07691 1.19201 0.96029 0.93562 0.78138 1.21405 0.96998 1.31684 1.06120 0.92608 1.24912 0.97662 0.94993 0.96451 1.69920 1.35672 1.33521 1.14392 0.86597 0.85072 0.78165 0.77799 1.20359 1.21272 1.20200 1.20072 0.78891 0.87239 0.84528 1.90624 1.44361 1.17523 1.86716 1.22454 1.03076 0.94421 0.90598 1.61572 1.28449 1.26133 1.04899 1.21865 0.97810 0.95028 0.89555 1.22934 0.96592 1.01980 0.96528 1.22979 0.92478 1.03272 1.02158 1.22971 1.05165 1.02179 0.92133 1.21487 0.84486 0.92375 0.97396 1.22376 1.01854 1.03066 0.93552 1.21680 1.00475 0.94714 0.97315 1.21836 0.99326 0.99063 1.00423 1.25357 0.84435 0.81269 0.79351 1.90677 1.40867 1.75518 1.33109 1.84772 1.62259 1.22086 1.63569 0.93175 0.92097 0.92324 0.90082 0.92040 0.95322 0.93938 0.92762 0.88856 0.89543 0.94052 0.90320 0.85053 0.88940 0.88865 0.88961 0.89266 0.92375 0.86805 0.91822 0.90870 0.90846 0.91884 0.93377 0.89612 0.74248 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 -0.17 -2.19 10.18 37.16 0.38 -1.82 16 2 C 0.11 1.66 5.85 -4.04 -0.02 1.63 16 3 N -0.60 -12.05 2.46 -175.06 -0.43 -12.48 16 4 C 0.25 6.32 5.16 -5.19 -0.03 6.29 16 5 C -0.52 -14.54 9.39 -34.44 -0.32 -14.86 16 6 H 0.06 1.55 7.81 -52.48 -0.41 1.14 16 7 C 0.06 1.74 5.46 -17.82 -0.10 1.64 16 8 N -0.90 -26.36 13.29 55.43 0.74 -25.62 16 9 Si 0.90 21.74 29.54 -169.99 -5.02 16.72 16 10 H -0.28 -6.55 7.11 56.52 0.40 -6.15 16 11 H -0.29 -6.88 7.11 56.52 0.40 -6.47 16 12 H -0.28 -6.76 7.11 56.52 0.40 -6.36 16 13 C 0.51 9.79 5.54 -10.98 -0.06 9.73 16 14 O -0.52 -11.84 13.43 5.56 0.07 -11.77 16 15 C 0.02 0.36 3.13 -4.97 -0.02 0.34 16 16 N -0.49 -6.63 2.80 -221.73 -0.62 -7.26 16 17 C 0.08 0.97 4.82 -3.82 -0.02 0.95 16 18 C -0.16 -1.76 4.34 -90.62 -0.39 -2.16 16 19 C -0.17 -1.75 10.18 -26.69 -0.27 -2.02 16 20 C -0.19 -1.71 10.25 -26.69 -0.27 -1.98 16 21 C 0.13 1.80 0.37 -132.75 -0.05 1.75 16 22 C -0.15 -2.28 6.80 37.15 0.25 -2.02 16 23 C -0.10 -1.30 3.82 -26.73 -0.10 -1.40 16 24 C -0.15 -1.92 8.22 37.16 0.31 -1.61 16 25 C 0.46 5.78 5.44 36.01 0.20 5.98 16 26 O -0.52 -7.65 16.96 -18.75 -0.32 -7.97 16 27 O -0.51 -5.04 9.43 -39.24 -0.37 -5.41 16 28 H 0.05 0.63 7.13 -51.93 -0.37 0.26 16 29 H 0.06 0.88 8.14 -51.93 -0.42 0.46 16 30 H 0.06 0.61 8.14 -51.93 -0.42 0.19 16 31 H 0.08 1.32 8.07 -51.92 -0.42 0.90 16 32 H 0.06 0.79 6.60 -51.93 -0.34 0.45 16 33 H 0.03 0.74 8.07 -51.93 -0.42 0.32 16 34 H 0.04 1.21 7.42 -51.93 -0.39 0.83 16 35 H 0.26 7.35 8.31 -40.82 -0.34 7.01 16 36 H 0.09 1.23 6.87 -51.93 -0.36 0.88 16 37 H 0.09 1.13 3.65 -51.93 -0.19 0.94 16 38 H 0.04 0.45 5.61 -51.93 -0.29 0.16 16 39 H 0.08 0.85 7.07 -51.93 -0.37 0.48 16 40 H 0.13 1.51 3.33 -51.93 -0.17 1.33 16 41 H 0.09 0.93 8.03 -51.93 -0.42 0.51 16 42 H 0.09 0.92 8.14 -51.93 -0.42 0.49 16 43 H 0.09 0.77 8.14 -51.93 -0.42 0.34 16 44 H 0.09 0.75 8.14 -51.93 -0.42 0.33 16 45 H 0.06 0.79 8.14 -51.93 -0.42 0.37 16 46 H 0.11 1.97 4.69 -51.93 -0.24 1.73 16 47 H 0.06 1.01 5.36 -51.93 -0.28 0.73 16 48 H 0.07 0.91 7.98 -51.93 -0.41 0.49 16 49 H 0.07 0.86 5.51 -51.93 -0.29 0.58 16 50 H 0.06 0.89 6.73 -51.93 -0.35 0.54 16 51 H 0.05 0.52 8.14 -51.93 -0.42 0.10 16 52 H 0.09 1.25 6.09 -51.93 -0.32 0.93 16 53 H 0.40 2.25 9.11 45.56 0.41 2.67 16 LS Contribution 398.62 15.07 6.01 6.01 Total: -1.00 -32.96 398.62 -8.18 -41.13 By element: Atomic # 1 Polarization: 13.90 SS G_CDS: -7.71 Total: 6.19 kcal Atomic # 6 Polarization: 0.97 SS G_CDS: -0.52 Total: 0.45 kcal Atomic # 7 Polarization: -45.04 SS G_CDS: -0.32 Total: -45.35 kcal Atomic # 8 Polarization: -24.53 SS G_CDS: -0.61 Total: -25.14 kcal Atomic # 14 Polarization: 21.74 SS G_CDS: -5.02 Total: 16.72 kcal Total LS contribution 6.01 Total: 6.01 kcal Total: -32.96 -8.18 -41.13 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. ZINC001596299739.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 -33.435 kcal (2) G-P(sol) polarization free energy of solvation -32.957 kcal (3) G-ENP(sol) elect.-nuc.-pol. free energy of system -66.391 kcal (4) G-CDS(sol) cavity-dispersion-solvent structure free energy -8.175 kcal (5) G-P-CDS(sol) = G-P(sol) + G-CDS(sol) = (2) + (4) -41.132 kcal (6) G-S(sol) free energy of system = (1) + (5) -74.567 kcal 1SCF WAS SPECIFIED, SO GEOMETRY OPTIMIZATION WAS NOT USED Total computer time = 0.90 seconds