Wall clock time and date at job start Tue Mar 31 2020 12:42:59 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 O 1.42901 * 1 3 3 C 1.35905 * 116.99604 * 2 1 4 4 C 1.38723 * 120.05884 * 359.72201 * 3 2 1 5 5 C 1.38145 * 119.94323 * 179.77076 * 4 3 2 6 6 C 1.38260 * 120.05692 * 0.50972 * 5 4 3 7 7 C 1.50706 * 119.94706 * 179.76915 * 6 5 4 8 8 C 1.52995 * 109.46738 * 269.97472 * 7 6 5 9 9 H 1.08993 * 109.47346 * 304.99835 * 8 7 6 10 10 C 1.53006 * 109.47331 * 65.00152 * 8 7 6 11 11 C 1.53002 * 109.46849 * 184.99797 * 8 7 6 12 12 N 1.46901 * 109.47304 * 175.00195 * 11 8 7 13 13 C 1.46899 * 111.00333 * 180.02562 * 12 11 8 14 14 C 1.53001 * 109.47351 * 179.97438 * 13 12 11 15 15 C 1.53001 * 109.47012 * 300.00268 * 14 13 12 16 16 C 1.53002 * 109.46870 * 59.99805 * 14 13 12 17 17 C 1.52996 * 109.47316 * 180.02562 * 14 13 12 18 18 C 1.50694 * 109.47292 * 180.02562 * 17 14 13 19 19 H 1.08001 * 120.00127 * 359.97438 * 18 17 14 20 20 C 1.37877 * 120.00413 * 179.97438 * 18 17 14 21 21 N 1.31512 * 119.99553 * 359.97438 * 20 18 17 22 22 Si 1.86800 * 120.00341 * 179.97438 * 20 18 17 23 23 H 1.48497 * 109.47051 * 60.00260 * 22 20 18 24 24 H 1.48503 * 109.46975 * 179.97438 * 22 20 18 25 25 H 1.48494 * 109.47176 * 300.00250 * 22 20 18 26 26 C 1.38268 * 120.10972 * 359.74026 * 6 5 4 27 27 C 1.38139 * 120.05510 * 0.02562 * 26 6 5 28 28 H 1.08996 * 109.46732 * 180.02562 * 1 2 3 29 29 H 1.08999 * 109.47144 * 300.00205 * 1 2 3 30 30 H 1.08998 * 109.47043 * 59.99803 * 1 2 3 31 31 H 1.08001 * 120.02769 * 0.02562 * 4 3 2 32 32 H 1.08006 * 119.97076 * 180.25587 * 5 4 3 33 33 H 1.09001 * 109.46891 * 29.97509 * 7 6 5 34 34 H 1.08994 * 109.47121 * 149.97471 * 7 6 5 35 35 H 1.08999 * 109.47127 * 179.97438 * 10 8 7 36 36 H 1.08998 * 109.46742 * 299.99863 * 10 8 7 37 37 H 1.08998 * 109.46824 * 59.99252 * 10 8 7 38 38 H 1.09002 * 109.47400 * 294.99694 * 11 8 7 39 39 H 1.09003 * 109.47486 * 55.00354 * 11 8 7 40 40 H 1.00909 * 110.99932 * 56.04222 * 12 11 8 41 41 H 1.09002 * 109.47024 * 299.99581 * 13 12 11 42 42 H 1.09001 * 109.47197 * 59.99978 * 13 12 11 43 43 H 1.08996 * 109.47353 * 59.99821 * 15 14 13 44 44 H 1.08994 * 109.47106 * 180.02562 * 15 14 13 45 45 H 1.09001 * 109.46946 * 299.99608 * 15 14 13 46 46 H 1.08994 * 109.47133 * 60.00455 * 16 14 13 47 47 H 1.09004 * 109.46713 * 180.02562 * 16 14 13 48 48 H 1.08996 * 109.47365 * 300.00099 * 16 14 13 49 49 H 1.09006 * 109.46826 * 300.00044 * 17 14 13 50 50 H 1.09001 * 109.47338 * 59.99966 * 17 14 13 51 51 H 0.97000 * 120.00138 * 179.97438 * 21 20 18 52 52 H 1.08008 * 119.97007 * 179.97438 * 26 6 5 53 53 H 1.08001 * 120.02451 * 179.97438 * 27 26 6 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 8 1.4290 0.0000 0.0000 3 6 2.0459 1.2110 0.0000 4 6 1.2915 2.3751 -0.0058 5 6 1.9210 3.6048 -0.0010 6 6 3.3018 3.6758 -0.0011 7 6 3.9860 5.0186 -0.0011 8 6 4.2180 5.4727 -1.4436 9 1 4.7709 4.7032 -1.9822 10 6 2.8696 5.7054 -2.1282 11 6 5.0223 6.7743 -1.4454 12 7 5.3478 7.1468 -2.8286 13 6 6.1222 8.3945 -2.8695 14 6 6.4421 8.7488 -4.3231 15 6 7.2594 7.6203 -4.9551 16 6 5.1381 8.9321 -5.1021 17 6 7.2491 10.0479 -4.3656 18 6 7.5637 10.3973 -5.7973 19 1 7.2225 9.7566 -6.5970 20 6 8.2871 11.5349 -6.0865 21 7 8.7021 12.3154 -5.1128 22 14 8.6776 11.9675 -7.8613 23 1 7.4120 12.1454 -8.6174 24 1 9.4598 13.2292 -7.9026 25 1 9.4709 10.8724 -8.4747 26 6 4.0560 2.5170 -0.0005 27 6 3.4313 1.2849 -0.0004 28 1 -0.3633 -1.0277 0.0005 29 1 -0.3633 0.5139 0.8900 30 1 -0.3633 0.5139 -0.8900 31 1 0.2129 2.3201 -0.0099 32 1 1.3341 4.5114 -0.0014 33 1 3.3578 5.7465 0.5124 34 1 4.9437 4.9384 0.5131 35 1 3.0350 6.0293 -3.1557 36 1 2.2967 4.7782 -2.1268 37 1 2.3167 6.4749 -1.5894 38 1 4.4321 7.5667 -0.9851 39 1 5.9439 6.6328 -0.8808 40 1 4.5122 7.2209 -3.3894 41 1 5.5400 9.1983 -2.4189 42 1 7.0514 8.2638 -2.3148 43 1 6.6849 6.6946 -4.9248 44 1 7.4877 7.8730 -5.9905 45 1 8.1884 7.4898 -4.4001 46 1 4.5558 9.7360 -4.6519 47 1 5.3661 9.1841 -6.1379 48 1 4.5636 8.0064 -5.0718 49 1 6.6672 10.8521 -3.9152 50 1 8.1781 9.9169 -3.8107 51 1 9.2113 13.1155 -5.3161 52 1 5.1345 2.5751 -0.0009 53 1 4.0209 0.3801 -0.0004 RHF calculation, no. of doubly occupied orbitals= 62 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 ZINC000157923422.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 12:42:59 Heat of formation + Delta-G solvation = -46.202085 kcal Electronic energy + Delta-G solvation = -26375.496031 eV Core-core repulsion = 22825.094454 eV Total energy + Delta-G solvation = -3550.401577 eV No. of doubly occupied orbitals = 62 Molecular weight (most abundant/longest-lived isotopes) = 319.225 amu Computer time = 0.87 seconds Orbital eigenvalues (eV) -40.48393 -38.57616 -37.67045 -36.01216 -33.31841 -32.02983 -31.36015 -30.30498 -27.94246 -27.14211 -26.65845 -26.29686 -25.77409 -24.04944 -22.90557 -22.19831 -21.31809 -20.00993 -18.45814 -17.82377 -16.54972 -16.26553 -16.10219 -16.05899 -15.44018 -14.87574 -14.73216 -14.55691 -14.28484 -13.95162 -13.85732 -13.69921 -13.31024 -13.00334 -12.82380 -12.72460 -12.35494 -12.33144 -12.12063 -11.96460 -11.79584 -11.69955 -11.46572 -11.12566 -10.96247 -10.90561 -10.87610 -10.77476 -10.67944 -10.65738 -10.44923 -10.20492 -10.08212 -9.64470 -9.25387 -8.98204 -8.80491 -8.31931 -8.29074 -8.01602 -5.93760 -3.93808 1.07549 1.15397 2.93842 3.36342 3.40822 3.43185 3.47337 4.39405 4.46393 4.51929 4.57106 4.69779 4.72180 4.74247 4.86328 5.05038 5.05786 5.10467 5.12120 5.16253 5.38257 5.41859 5.49823 5.56297 5.66223 5.71802 5.73316 5.79585 5.83750 5.88202 5.94569 6.01962 6.03985 6.09050 6.22309 6.25986 6.31834 6.38317 6.46780 6.50291 6.55143 6.70334 6.82922 6.86303 7.07460 7.24240 7.27923 7.30114 7.46684 7.71880 7.76290 7.89222 8.06637 8.51315 9.11365 9.68730 11.17844 Molecular weight = 319.23amu Principal moments of inertia in cm(-1) A = 0.034251 B = 0.001799 C = 0.001781 Principal moments of inertia in units of 10**(-40)*gram-cm**2 A = 817.288160 B =15562.768884 C =15715.745545 Net atomic charges, atomic populations, and dipole contributions calculated with CM2 Atom NO. Type Charge No. of electrons 1 C 0.028 3.972 2 O -0.320 6.320 3 C 0.117 3.883 4 C -0.207 4.207 5 C -0.076 4.076 6 C -0.109 4.109 7 C -0.073 4.073 8 C -0.083 4.083 9 H 0.081 0.919 10 C -0.152 4.152 11 C 0.062 3.938 12 N -0.687 5.687 13 C 0.070 3.930 14 C -0.059 4.059 15 C -0.116 4.116 16 C -0.129 4.129 17 C 0.034 3.966 18 C -0.507 4.507 19 H 0.058 0.942 20 C 0.054 3.946 21 N -0.898 5.898 22 Si 0.888 3.112 23 H -0.278 1.278 24 H -0.289 1.289 25 H -0.277 1.277 26 C -0.077 4.077 27 C -0.149 4.149 28 H 0.098 0.902 29 H 0.054 0.946 30 H 0.055 0.945 31 H 0.125 0.875 32 H 0.124 0.876 33 H 0.070 0.930 34 H 0.073 0.927 35 H 0.058 0.942 36 H 0.057 0.943 37 H 0.050 0.950 38 H 0.024 0.976 39 H 0.069 0.931 40 H 0.337 0.663 41 H 0.021 0.979 42 H 0.065 0.935 43 H 0.042 0.958 44 H 0.053 0.947 45 H 0.039 0.961 46 H 0.039 0.961 47 H 0.064 0.936 48 H 0.032 0.968 49 H 0.012 0.988 50 H 0.015 0.985 51 H 0.259 0.741 52 H 0.130 0.870 53 H 0.129 0.871 For the charges calculated by CM2: Dipole moment (debyes) X Y Z Total from point charges -16.531 -21.664 12.975 30.182 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 -0.067 4.067 2 O -0.234 6.234 3 C 0.073 3.927 4 C -0.226 4.226 5 C -0.094 4.094 6 C -0.109 4.109 7 C -0.111 4.111 8 C -0.102 4.102 9 H 0.099 0.901 10 C -0.209 4.209 11 C -0.067 4.067 12 N -0.320 5.320 13 C -0.059 4.059 14 C -0.059 4.059 15 C -0.173 4.173 16 C -0.186 4.186 17 C -0.003 4.003 18 C -0.545 4.545 19 H 0.076 0.924 20 C -0.146 4.146 21 N -0.538 5.538 22 Si 0.716 3.284 23 H -0.204 1.204 24 H -0.215 1.215 25 H -0.203 1.203 26 C -0.095 4.095 27 C -0.168 4.168 28 H 0.117 0.883 29 H 0.073 0.927 30 H 0.074 0.926 31 H 0.143 0.857 32 H 0.142 0.858 33 H 0.088 0.912 34 H 0.092 0.908 35 H 0.077 0.923 36 H 0.076 0.924 37 H 0.069 0.931 38 H 0.042 0.958 39 H 0.087 0.913 40 H 0.158 0.842 41 H 0.040 0.960 42 H 0.083 0.917 43 H 0.061 0.939 44 H 0.072 0.928 45 H 0.058 0.942 46 H 0.058 0.942 47 H 0.083 0.917 48 H 0.051 0.949 49 H 0.030 0.970 50 H 0.033 0.967 51 H 0.069 0.931 52 H 0.148 0.852 53 H 0.147 0.853 Dipole moment (debyes) X Y Z Total from point charges -15.799 -22.086 12.978 30.097 hybrid contribution -0.712 1.210 -0.708 1.573 sum -16.511 -20.875 12.270 29.308 Atomic orbital electron populations 1.23038 0.78482 1.03860 1.01342 1.86063 1.21319 1.27126 1.88897 1.19033 0.92413 0.84074 0.97229 1.21208 0.99888 0.92419 1.09082 1.20856 0.94083 0.96892 0.97558 1.19807 0.93460 0.95344 1.02268 1.20600 1.00359 0.92941 0.97168 1.21120 0.96401 0.97849 0.94836 0.90109 1.21928 0.96823 1.01430 1.00707 1.21982 0.98568 0.95149 0.91047 1.60590 1.26097 1.35438 1.09867 1.22096 0.96916 0.88302 0.98548 1.20632 0.95802 0.98080 0.91425 1.21593 0.98472 0.96605 1.00619 1.21766 0.96565 0.98503 1.01762 1.19116 0.94273 0.89909 0.97045 1.21209 1.33358 1.07387 0.92595 0.92357 1.25018 0.96214 0.96604 0.96781 1.69956 1.38042 1.14478 1.31285 0.86720 0.78361 0.77628 0.85651 1.20393 1.21463 1.20317 1.20909 0.99999 0.90945 0.97616 1.20425 0.91331 0.98714 1.06333 0.88313 0.92728 0.92644 0.85696 0.85850 0.91182 0.90845 0.92327 0.92422 0.93132 0.95783 0.91295 0.84247 0.96027 0.91660 0.93883 0.92760 0.94202 0.94155 0.91741 0.94877 0.96966 0.96696 0.93143 0.85224 0.85333 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 0.03 0.15 9.81 101.05 0.99 1.14 16 2 O -0.32 -2.93 10.50 -19.44 -0.20 -3.14 16 3 C 0.12 1.13 6.69 -39.22 -0.26 0.86 16 4 C -0.21 -1.77 9.04 -39.44 -0.36 -2.13 16 5 C -0.08 -0.65 7.95 -39.61 -0.32 -0.97 16 6 C -0.11 -0.98 4.71 -104.60 -0.49 -1.47 16 7 C -0.07 -0.63 4.84 -27.88 -0.13 -0.76 16 8 C -0.08 -0.83 2.59 -90.62 -0.23 -1.07 16 9 H 0.08 0.91 8.14 -51.93 -0.42 0.49 16 10 C -0.15 -1.46 8.53 37.16 0.32 -1.15 16 11 C 0.06 0.74 5.14 -3.82 -0.02 0.72 16 12 N -0.69 -9.98 5.71 -113.77 -0.65 -10.63 16 13 C 0.07 1.23 4.65 -3.82 -0.02 1.21 16 14 C -0.06 -1.19 0.60 -154.51 -0.09 -1.28 16 15 C -0.12 -2.28 8.06 37.16 0.30 -1.98 16 16 C -0.13 -2.42 7.89 37.16 0.29 -2.13 16 17 C 0.03 0.87 4.04 -27.89 -0.11 0.75 16 18 C -0.51 -13.99 7.65 -34.44 -0.26 -14.25 16 19 H 0.06 1.56 5.68 -52.49 -0.30 1.26 16 20 C 0.05 1.55 5.46 -17.82 -0.10 1.45 16 21 N -0.90 -26.99 13.29 55.43 0.74 -26.26 16 22 Si 0.89 21.73 29.54 -169.99 -5.02 16.71 16 23 H -0.28 -6.69 7.11 56.52 0.40 -6.29 16 24 H -0.29 -7.04 7.11 56.52 0.40 -6.64 16 25 H -0.28 -6.69 7.11 56.52 0.40 -6.29 16 26 C -0.08 -0.69 9.69 -39.61 -0.38 -1.07 16 27 C -0.15 -1.40 9.99 -39.44 -0.39 -1.79 16 28 H 0.10 0.33 8.14 -51.93 -0.42 -0.09 16 29 H 0.05 0.24 7.67 -51.93 -0.40 -0.16 16 30 H 0.05 0.26 7.65 -51.93 -0.40 -0.14 16 31 H 0.13 0.82 6.30 -52.49 -0.33 0.49 16 32 H 0.12 0.90 8.04 -52.48 -0.42 0.47 16 33 H 0.07 0.57 8.08 -51.93 -0.42 0.15 16 34 H 0.07 0.60 8.08 -51.93 -0.42 0.18 16 35 H 0.06 0.61 6.68 -51.93 -0.35 0.26 16 36 H 0.06 0.54 6.27 -51.93 -0.33 0.21 16 37 H 0.05 0.46 8.14 -51.93 -0.42 0.04 16 38 H 0.02 0.29 8.14 -51.93 -0.42 -0.13 16 39 H 0.07 0.84 8.14 -51.93 -0.42 0.41 16 40 H 0.34 4.74 5.03 -39.29 -0.20 4.55 16 41 H 0.02 0.38 8.14 -51.93 -0.42 -0.04 16 42 H 0.06 1.18 8.14 -51.93 -0.42 0.76 16 43 H 0.04 0.76 7.60 -51.93 -0.39 0.37 16 44 H 0.05 1.14 6.62 -51.93 -0.34 0.79 16 45 H 0.04 0.79 8.14 -51.93 -0.42 0.37 16 46 H 0.04 0.75 8.14 -51.93 -0.42 0.33 16 47 H 0.06 1.31 6.62 -51.93 -0.34 0.97 16 48 H 0.03 0.53 6.57 -51.93 -0.34 0.19 16 49 H 0.01 0.33 8.14 -51.93 -0.42 -0.09 16 50 H 0.01 0.41 8.14 -51.93 -0.42 -0.02 16 51 H 0.26 7.41 8.31 -40.82 -0.34 7.07 16 52 H 0.13 0.98 8.06 -52.48 -0.42 0.56 16 53 H 0.13 1.05 8.06 -52.49 -0.42 0.63 16 LS Contribution 408.56 15.07 6.16 6.16 Total: -1.00 -30.54 408.56 -9.87 -40.40 By element: Atomic # 1 Polarization: 10.26 SS G_CDS: -9.61 Total: 0.65 kcal Atomic # 6 Polarization: -22.62 SS G_CDS: -1.28 Total: -23.90 kcal Atomic # 7 Polarization: -36.97 SS G_CDS: 0.09 Total: -36.88 kcal Atomic # 8 Polarization: -2.93 SS G_CDS: -0.20 Total: -3.14 kcal Atomic # 14 Polarization: 21.73 SS G_CDS: -5.02 Total: 16.71 kcal Total LS contribution 6.16 Total: 6.16 kcal Total: -30.54 -9.87 -40.40 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. ZINC000157923422.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 -5.798 kcal (2) G-P(sol) polarization free energy of solvation -30.537 kcal (3) G-ENP(sol) elect.-nuc.-pol. free energy of system -36.335 kcal (4) G-CDS(sol) cavity-dispersion-solvent structure free energy -9.867 kcal (5) G-P-CDS(sol) = G-P(sol) + G-CDS(sol) = (2) + (4) -40.404 kcal (6) G-S(sol) free energy of system = (1) + (5) -46.202 kcal 1SCF WAS SPECIFIED, SO GEOMETRY OPTIMIZATION WAS NOT USED Total computer time = 0.87 seconds