Wall clock time and date at job start Wed Apr 1 2020 02:13:43 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 1.50708 * 1 3 3 C 1.38255 * 119.99925 * 2 1 4 4 C 1.38211 * 119.99685 * 180.27883 * 3 2 1 5 5 C 1.38253 * 120.00400 * 359.73793 * 4 3 2 6 6 C 1.38217 * 119.99601 * 0.02562 * 5 4 3 7 7 C 1.38214 * 119.99937 * 179.76335 * 2 1 3 8 8 C 1.50700 * 120.00211 * 0.02562 * 7 2 1 9 9 H 1.09002 * 115.54634 * 334.00058 * 8 7 2 10 10 C 1.53000 * 117.49943 * 188.33448 * 8 7 2 11 11 C 1.53003 * 60.03017 * 252.49204 * 10 8 7 12 12 H 1.09000 * 117.49711 * 107.50275 * 11 10 8 13 13 C 1.50698 * 117.49966 * 252.51992 * 11 10 8 14 14 O 1.21280 * 119.99895 * 68.60765 * 13 11 10 15 15 N 1.34780 * 120.00088 * 248.60904 * 13 11 10 16 16 C 1.46499 * 119.99907 * 180.02562 * 15 13 11 17 17 H 1.08997 * 110.64094 * 34.30056 * 16 15 13 18 18 C 1.54320 * 110.72090 * 271.15451 * 16 15 13 19 19 N 1.47490 * 107.03775 * 263.79374 * 18 16 15 20 20 C 1.36935 * 125.58948 * 181.00783 * 19 18 16 21 21 H 1.08002 * 119.99941 * 173.91667 * 20 19 18 22 22 C 1.38816 * 120.00283 * 353.91248 * 20 19 18 23 23 N 1.31614 * 119.99878 * 6.83251 * 22 20 19 24 24 Si 1.86798 * 119.99914 * 186.83305 * 22 20 19 25 25 H 1.48498 * 109.47307 * 94.98836 * 24 22 20 26 26 H 1.48504 * 109.46842 * 214.98760 * 24 22 20 27 27 H 1.48504 * 109.47232 * 334.98426 * 24 22 20 28 28 C 1.47421 * 108.75897 * 1.02540 * 19 18 16 29 29 C 1.54918 * 104.83143 * 335.89402 * 28 19 18 30 30 C 1.53003 * 111.00380 * 278.93609 * 29 28 19 31 31 C 1.52999 * 111.00302 * 155.08382 * 29 28 19 32 32 H 1.08996 * 109.46914 * 270.23358 * 1 2 3 33 33 H 1.08992 * 109.46928 * 30.23335 * 1 2 3 34 34 H 1.08996 * 109.46752 * 150.23314 * 1 2 3 35 35 H 1.08002 * 120.00279 * 359.97438 * 3 2 1 36 36 H 1.08005 * 119.99950 * 179.72264 * 4 3 2 37 37 H 1.07998 * 120.00375 * 179.97438 * 5 4 3 38 38 H 1.08004 * 119.99631 * 179.97438 * 6 5 4 39 39 H 1.08993 * 117.49677 * 359.97438 * 10 8 7 40 40 H 1.09007 * 117.49760 * 144.99334 * 10 8 7 41 41 H 0.97005 * 119.99617 * 0.02562 * 15 13 11 42 42 H 1.09006 * 109.88448 * 23.25252 * 18 16 15 43 43 H 1.09001 * 109.88305 * 144.41199 * 18 16 15 44 44 H 0.97002 * 120.00122 * 179.97438 * 23 22 20 45 45 H 1.08995 * 110.36378 * 217.05796 * 28 19 18 46 46 H 1.08991 * 110.36825 * 94.72918 * 28 19 18 47 47 H 1.09000 * 109.47232 * 172.19561 * 30 29 28 48 48 H 1.09000 * 109.47208 * 292.19904 * 30 29 28 49 49 H 1.09004 * 109.47241 * 52.19499 * 30 29 28 50 50 H 1.08993 * 109.47278 * 307.80584 * 31 29 28 51 51 H 1.09007 * 109.46993 * 67.80308 * 31 29 28 52 52 H 1.08998 * 109.46645 * 187.79987 * 31 29 28 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 1.5071 0.0000 0.0000 3 6 2.1983 1.1973 0.0000 4 6 3.5804 1.1973 -0.0058 5 6 4.2718 0.0000 -0.0062 6 6 3.5806 -1.1970 -0.0012 7 6 2.1981 -1.1970 0.0049 8 6 1.4447 -2.5021 0.0098 9 1 0.4440 -2.4655 0.4403 10 6 2.2543 -3.7845 0.2118 11 6 1.6744 -3.4557 -1.1654 12 1 2.3706 -3.1391 -1.9421 13 6 0.4996 -4.2722 -1.6387 14 8 -0.5770 -4.1593 -1.0919 15 7 0.6454 -5.1280 -2.6697 16 6 -0.4969 -5.9214 -3.1302 17 1 -1.4234 -5.3567 -3.0271 18 6 -0.5817 -7.2553 -2.3588 19 7 0.0836 -8.2773 -3.1884 20 6 0.2082 -9.6036 -2.8715 21 1 0.6267 -10.2934 -3.5894 22 6 -0.2034 -10.0616 -1.6273 23 7 -0.8351 -9.2520 -0.8041 24 14 0.1393 -11.8269 -1.1217 25 1 1.3958 -11.8806 -0.3320 26 1 -0.9865 -12.3326 -0.2957 27 1 0.2809 -12.6709 -2.3354 28 6 0.5924 -7.6353 -4.4141 29 6 -0.2922 -6.3770 -4.5991 30 6 -1.6279 -6.7369 -5.2529 31 6 0.4410 -5.3055 -5.4086 32 1 -0.3633 0.0042 1.0276 33 1 -0.3633 0.8878 -0.5174 34 1 -0.3633 -0.8920 -0.5102 35 1 1.6584 2.1327 -0.0004 36 1 4.1205 2.1326 -0.0104 37 1 5.3517 0.0000 -0.0111 38 1 4.1207 -2.1323 -0.0019 39 1 3.3319 -3.6842 0.3408 40 1 1.7862 -4.5917 0.7753 41 1 1.5066 -5.2186 -3.1067 42 1 -0.0712 -7.1623 -1.4002 43 1 -1.6255 -7.5262 -2.2004 44 1 -1.1230 -9.5721 0.0652 45 1 0.4822 -8.3052 -5.2669 46 1 1.6365 -7.3496 -4.2874 47 1 -2.2826 -5.8654 -5.2453 48 1 -1.4554 -7.0528 -6.2817 49 1 -2.0972 -7.5488 -4.6974 50 1 1.4172 -5.1172 -4.9619 51 1 0.5713 -5.6507 -6.4343 52 1 -0.1432 -4.3853 -5.4063 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 ZINC000977325147.mol2 52 1SCF WAS SPECIFIED, SO GEOMETRY OPTIMIZATION WAS NOT USED SCF FIELD WAS ACHIEVED Wall clock time and date at job start Wed Apr 1 2020 02:13:43 Heat of formation + Delta-G solvation = 32.130030 kcal Electronic energy + Delta-G solvation = -30270.125828 eV Core-core repulsion = 26428.554274 eV Total energy + Delta-G solvation = -3841.571555 eV No. of doubly occupied orbitals = 65 Molecular weight (most abundant/longest-lived isotopes) = 342.205 amu Computer time = 1.43 seconds Orbital eigenvalues (eV) -40.36194 -39.48538 -38.12358 -36.11499 -33.82177 -33.00908 -32.90547 -30.74821 -30.66370 -28.21531 -27.06669 -26.84351 -25.62904 -24.56002 -23.98458 -22.85499 -21.54446 -20.56959 -20.08020 -19.67442 -18.60471 -17.40537 -16.69088 -16.52020 -15.81274 -15.45324 -14.99906 -14.78711 -14.58614 -14.12611 -14.02058 -13.85955 -13.84149 -13.73039 -13.23312 -13.22349 -12.63165 -12.43854 -12.38483 -12.26295 -12.05514 -11.96934 -11.93604 -11.68262 -11.39758 -11.28831 -11.07182 -11.01129 -10.97390 -10.77874 -10.73250 -10.43379 -10.37117 -10.21825 -9.98748 -9.86724 -9.62933 -9.46608 -8.92289 -8.62831 -8.56865 -8.39664 -6.80687 -5.69084 -3.02668 1.13750 1.22248 2.84503 3.38474 3.40976 3.45996 3.48459 3.63922 4.06041 4.49594 4.51887 4.64473 4.74727 4.80534 4.86579 4.90191 4.96026 5.09781 5.18625 5.22015 5.29528 5.33017 5.40861 5.50739 5.52652 5.56475 5.62198 5.66235 5.77051 5.81971 5.88039 5.93049 5.99938 6.03525 6.04040 6.08538 6.17060 6.21298 6.25755 6.33998 6.37727 6.40279 6.55327 6.59050 6.62841 6.68863 6.77950 6.84846 6.97665 7.55304 7.68376 7.84296 7.98759 8.26387 8.66941 9.22469 9.83904 10.50128 11.41967 Molecular weight = 342.20amu Principal moments of inertia in cm(-1) A = 0.013949 B = 0.002692 C = 0.002473 Principal moments of inertia in units of 10**(-40)*gram-cm**2 A = 2006.899380 B =10399.047852 C =11317.798827 Net atomic charges, atomic populations, and dipole contributions calculated with CM2 Atom NO. Type Charge No. of electrons 1 C -0.122 4.122 2 C -0.074 4.074 3 C -0.121 4.121 4 C -0.123 4.123 5 C -0.125 4.125 6 C -0.116 4.116 7 C -0.050 4.050 8 C -0.088 4.088 9 H 0.129 0.871 10 C -0.143 4.143 11 C -0.173 4.173 12 H 0.120 0.880 13 C 0.541 3.459 14 O -0.542 6.542 15 N -0.705 5.705 16 C 0.124 3.876 17 H 0.087 0.913 18 C 0.176 3.824 19 N -0.603 5.603 20 C -0.230 4.230 21 H 0.077 0.923 22 C -0.006 4.006 23 N -0.916 5.916 24 Si 0.908 3.092 25 H -0.290 1.290 26 H -0.292 1.292 27 H -0.281 1.281 28 C 0.144 3.856 29 C -0.089 4.089 30 C -0.126 4.126 31 C -0.130 4.130 32 H 0.071 0.929 33 H 0.064 0.936 34 H 0.077 0.923 35 H 0.121 0.879 36 H 0.119 0.881 37 H 0.120 0.880 38 H 0.124 0.876 39 H 0.105 0.895 40 H 0.108 0.892 41 H 0.396 0.604 42 H 0.052 0.948 43 H 0.049 0.951 44 H 0.252 0.748 45 H 0.040 0.960 46 H 0.016 0.984 47 H 0.047 0.953 48 H 0.052 0.948 49 H 0.069 0.931 50 H 0.050 0.950 51 H 0.054 0.946 52 H 0.052 0.948 For the charges calculated by CM2: Dipole moment (debyes) X Y Z Total from point charges 7.714 19.814 -2.504 21.409 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 -0.178 4.178 2 C -0.074 4.074 3 C -0.139 4.139 4 C -0.141 4.141 5 C -0.143 4.143 6 C -0.134 4.134 7 C -0.050 4.050 8 C -0.107 4.107 9 H 0.147 0.853 10 C -0.181 4.181 11 C -0.194 4.194 12 H 0.138 0.862 13 C 0.327 3.673 14 O -0.419 6.419 15 N -0.354 5.354 16 C 0.020 3.980 17 H 0.105 0.895 18 C 0.050 3.950 19 N -0.330 5.330 20 C -0.358 4.358 21 H 0.095 0.905 22 C -0.203 4.203 23 N -0.563 5.563 24 Si 0.739 3.261 25 H -0.217 1.217 26 H -0.218 1.218 27 H -0.207 1.207 28 C 0.018 3.982 29 C -0.091 4.091 30 C -0.184 4.184 31 C -0.188 4.188 32 H 0.090 0.910 33 H 0.083 0.917 34 H 0.095 0.905 35 H 0.139 0.861 36 H 0.137 0.863 37 H 0.138 0.862 38 H 0.142 0.858 39 H 0.123 0.877 40 H 0.126 0.874 41 H 0.230 0.770 42 H 0.070 0.930 43 H 0.067 0.933 44 H 0.063 0.937 45 H 0.058 0.942 46 H 0.033 0.967 47 H 0.066 0.934 48 H 0.071 0.929 49 H 0.088 0.912 50 H 0.069 0.931 51 H 0.073 0.927 52 H 0.071 0.929 Dipole moment (debyes) X Y Z Total from point charges 6.854 19.722 -1.943 20.970 hybrid contribution 0.762 -1.029 0.099 1.285 sum 7.617 18.693 -1.844 20.269 Atomic orbital electron populations 1.20882 0.90988 1.03345 1.02586 1.19773 0.96290 0.92304 0.98996 1.21016 0.94255 0.97353 1.01264 1.21109 0.94309 0.97989 1.00706 1.21084 0.99745 0.92446 1.01031 1.21088 0.93612 0.98376 1.00348 1.19044 0.92999 0.92853 1.00065 1.21094 1.00959 0.87705 1.00921 0.85343 1.23137 1.00038 0.98727 0.96165 1.22347 1.00414 1.03124 0.93518 0.86181 1.19439 0.88486 0.79525 0.79852 1.90687 1.27720 1.67440 1.56062 1.45911 1.13999 1.41449 1.34087 1.22461 0.88240 0.93853 0.93485 0.89536 1.21605 0.97846 0.82761 0.92762 1.44547 1.65297 1.04976 1.18135 1.19023 1.36041 0.82748 0.98036 0.90519 1.24823 1.00691 0.98033 0.96713 1.69977 1.42688 1.34269 1.09351 0.86159 0.77446 0.84246 0.78270 1.21718 1.21815 1.20694 1.21618 0.94105 0.91741 0.90739 1.22011 0.97091 0.96282 0.93722 1.21601 0.95413 1.01512 0.99834 1.21671 0.99628 0.98089 0.99428 0.91033 0.91699 0.90452 0.86142 0.86290 0.86185 0.85774 0.87653 0.87358 0.76956 0.93030 0.93274 0.93730 0.94191 0.96691 0.93355 0.92903 0.91224 0.93054 0.92685 0.92887 Number of geometries 1 Number of calculations of the screened coulomb radii 1 The total number of SCF iterations 17. 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 -0.12 -1.21 9.33 36.01 0.34 -0.87 16 2 C -0.07 -0.80 5.88 -104.62 -0.62 -1.41 16 3 C -0.12 -1.14 9.70 -39.58 -0.38 -1.53 16 4 C -0.12 -1.08 10.05 -39.59 -0.40 -1.48 16 5 C -0.13 -1.13 10.05 -39.58 -0.40 -1.53 16 6 C -0.12 -1.17 9.30 -39.58 -0.37 -1.54 16 7 C -0.05 -0.56 5.61 -104.63 -0.59 -1.15 16 8 C -0.09 -1.11 4.65 -91.74 -0.43 -1.53 16 9 H 0.13 1.80 6.45 -51.93 -0.33 1.46 16 10 C -0.14 -1.75 9.56 -26.73 -0.26 -2.01 16 11 C -0.17 -2.26 5.83 -91.73 -0.53 -2.79 16 12 H 0.12 1.32 8.14 -51.93 -0.42 0.90 16 13 C 0.54 9.23 7.61 -10.99 -0.08 9.15 16 14 O -0.54 -11.25 15.94 5.56 0.09 -11.16 16 15 N -0.70 -11.69 4.51 -52.03 -0.23 -11.93 16 16 C 0.12 2.37 2.54 -66.10 -0.17 2.20 16 17 H 0.09 1.73 7.53 -51.93 -0.39 1.33 16 18 C 0.18 4.30 4.82 -2.81 -0.01 4.29 16 19 N -0.60 -14.98 3.39 -169.70 -0.58 -15.55 16 20 C -0.23 -6.34 10.26 -15.06 -0.15 -6.50 16 21 H 0.08 2.05 7.84 -52.49 -0.41 1.64 16 22 C -0.01 -0.17 5.48 -17.43 -0.10 -0.26 16 23 N -0.92 -27.26 10.36 55.49 0.58 -26.69 16 24 Si 0.91 22.21 29.56 -169.99 -5.02 17.19 16 25 H -0.29 -7.11 7.11 56.52 0.40 -6.70 16 26 H -0.29 -7.23 7.11 56.52 0.40 -6.83 16 27 H -0.28 -6.67 7.11 56.52 0.40 -6.27 16 28 C 0.14 2.84 6.14 -2.53 -0.02 2.83 16 29 C -0.09 -1.48 0.83 -152.35 -0.13 -1.60 16 30 C -0.13 -2.01 8.57 37.16 0.32 -1.69 16 31 C -0.13 -1.68 8.22 37.16 0.31 -1.38 16 32 H 0.07 0.66 8.14 -51.93 -0.42 0.24 16 33 H 0.06 0.55 8.09 -51.93 -0.42 0.13 16 34 H 0.08 0.89 6.65 -51.93 -0.35 0.54 16 35 H 0.12 0.90 8.06 -52.49 -0.42 0.48 16 36 H 0.12 0.78 8.06 -52.48 -0.42 0.36 16 37 H 0.12 0.83 8.06 -52.49 -0.42 0.41 16 38 H 0.12 1.09 6.02 -52.48 -0.32 0.77 16 39 H 0.11 1.03 6.18 -51.93 -0.32 0.71 16 40 H 0.11 1.51 8.14 -51.93 -0.42 1.08 16 41 H 0.40 5.71 7.01 -40.82 -0.29 5.43 16 42 H 0.05 1.45 7.27 -51.93 -0.38 1.07 16 43 H 0.05 1.36 7.56 -51.93 -0.39 0.97 16 44 H 0.25 7.36 8.31 -40.82 -0.34 7.02 16 45 H 0.04 0.78 8.05 -51.93 -0.42 0.36 16 46 H 0.02 0.29 7.98 -51.93 -0.41 -0.12 16 47 H 0.05 0.69 8.14 -51.93 -0.42 0.27 16 48 H 0.05 0.74 8.14 -51.93 -0.42 0.32 16 49 H 0.07 1.31 7.91 -51.93 -0.41 0.90 16 50 H 0.05 0.61 6.43 -51.93 -0.33 0.28 16 51 H 0.05 0.64 8.14 -51.93 -0.42 0.22 16 52 H 0.05 0.66 8.14 -51.93 -0.42 0.23 16 LS Contribution 409.97 15.07 6.18 6.18 Total: -1.00 -32.39 409.97 -11.19 -43.59 By element: Atomic # 1 Polarization: 15.73 SS G_CDS: -8.54 Total: 7.19 kcal Atomic # 6 Polarization: -5.15 SS G_CDS: -3.66 Total: -8.81 kcal Atomic # 7 Polarization: -53.93 SS G_CDS: -0.24 Total: -54.17 kcal Atomic # 8 Polarization: -11.25 SS G_CDS: 0.09 Total: -11.16 kcal Atomic # 14 Polarization: 22.21 SS G_CDS: -5.02 Total: 17.19 kcal Total LS contribution 6.18 Total: 6.18 kcal Total: -32.39 -11.19 -43.59 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. ZINC000977325147.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 75.718 kcal (2) G-P(sol) polarization free energy of solvation -32.395 kcal (3) G-ENP(sol) elect.-nuc.-pol. free energy of system 43.323 kcal (4) G-CDS(sol) cavity-dispersion-solvent structure free energy -11.193 kcal (5) G-P-CDS(sol) = G-P(sol) + G-CDS(sol) = (2) + (4) -43.588 kcal (6) G-S(sol) free energy of system = (1) + (5) 32.130 kcal 1SCF WAS SPECIFIED, SO GEOMETRY OPTIMIZATION WAS NOT USED Total computer time = 1.43 seconds