Wall clock time and date at job start Sat Apr 11 2020 06:10:38 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 1.45201 * 1 3 3 C 1.34631 * 117.00031 * 2 1 4 4 O 1.21503 * 120.00384 * 0.02562 * 3 2 1 5 5 N 1.34780 * 119.99842 * 180.02562 * 3 2 1 6 6 C 1.46925 * 120.63150 * 179.97438 * 5 3 2 7 7 C 1.53202 * 108.89303 * 126.29840 * 6 5 3 8 8 C 1.53345 * 109.14723 * 54.57511 * 7 6 5 9 9 C 1.50701 * 109.41789 * 178.67402 * 8 7 6 10 10 O 1.21277 * 119.99645 * 87.92464 * 9 8 7 11 11 N 1.34780 * 120.00071 * 267.92554 * 9 8 7 12 12 C 1.46497 * 119.99706 * 4.10680 * 11 9 8 13 13 C 1.50698 * 109.47071 * 84.29034 * 12 11 9 14 14 H 1.08007 * 119.99963 * 359.97438 * 13 12 11 15 15 C 1.37874 * 120.00188 * 180.02562 * 13 12 11 16 16 N 1.31519 * 119.99911 * 359.97438 * 15 13 12 17 17 Si 1.86801 * 120.00360 * 179.97438 * 15 13 12 18 18 H 1.48503 * 109.47196 * 89.99166 * 17 15 13 19 19 H 1.48499 * 109.47372 * 209.99580 * 17 15 13 20 20 H 1.48500 * 109.46939 * 329.99538 * 17 15 13 21 21 C 1.46499 * 119.99540 * 184.11089 * 11 9 8 22 22 C 1.52998 * 109.47367 * 87.53562 * 21 11 9 23 23 C 1.52996 * 109.47371 * 54.83975 * 22 21 11 24 24 C 1.53005 * 109.47198 * 174.84075 * 22 21 11 25 25 C 1.53009 * 109.46801 * 294.83702 * 22 21 11 26 26 C 1.53040 * 109.61115 * 298.71330 * 8 7 6 27 27 C 1.46924 * 120.62945 * 359.97438 * 5 3 2 28 28 H 1.08994 * 109.47458 * 179.97438 * 1 2 3 29 29 H 1.09004 * 109.46681 * 300.00060 * 1 2 3 30 30 H 1.08997 * 109.47067 * 59.99565 * 1 2 3 31 31 H 1.08992 * 109.59061 * 246.15584 * 6 5 3 32 32 H 1.09001 * 109.58607 * 6.44023 * 6 5 3 33 33 H 1.08997 * 109.49848 * 174.66138 * 7 6 5 34 34 H 1.09001 * 109.49608 * 294.75585 * 7 6 5 35 35 H 1.09004 * 109.42204 * 58.75649 * 8 7 6 36 36 H 1.09007 * 109.46571 * 204.28220 * 12 11 9 37 37 H 1.08991 * 109.47553 * 324.28118 * 12 11 9 38 38 H 0.96996 * 119.99730 * 180.02562 * 16 15 13 39 39 H 1.09004 * 109.46717 * 207.53272 * 21 11 9 40 40 H 1.08997 * 109.47541 * 327.52825 * 21 11 9 41 41 H 1.08994 * 109.47418 * 60.00066 * 23 22 21 42 42 H 1.08999 * 109.47230 * 180.02562 * 23 22 21 43 43 H 1.09005 * 109.47005 * 300.00042 * 23 22 21 44 44 H 1.09003 * 109.46889 * 59.99947 * 24 22 21 45 45 H 1.08999 * 109.46833 * 179.97438 * 24 22 21 46 46 H 1.08994 * 109.46908 * 299.99517 * 24 22 21 47 47 H 1.09003 * 109.46661 * 64.69968 * 25 22 21 48 48 H 1.08999 * 109.46886 * 184.70218 * 25 22 21 49 49 H 1.08998 * 109.46676 * 304.70314 * 25 22 21 50 50 H 1.08991 * 109.49758 * 301.42375 * 26 8 7 51 51 H 1.08998 * 109.52062 * 181.33727 * 26 8 7 52 52 H 1.08995 * 109.58743 * 353.41600 * 27 5 3 53 53 H 1.09003 * 109.58678 * 113.70184 * 27 5 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 8 1.4520 0.0000 0.0000 3 6 2.0632 1.1996 0.0000 4 8 1.4015 2.2186 0.0005 5 7 3.4092 1.2701 -0.0005 6 6 4.0906 2.5717 -0.0011 7 6 5.0814 2.6135 1.1667 8 6 6.0234 1.4074 1.0705 9 6 7.0216 1.4601 2.1983 10 8 6.7547 0.9556 3.2683 11 7 8.2110 2.0679 2.0177 12 6 8.4982 2.7552 0.7563 13 6 7.9374 4.1530 0.8068 14 1 7.4184 4.4951 1.6901 15 6 8.0857 4.9949 -0.2749 16 7 8.7172 4.5783 -1.3507 17 14 7.3899 6.7274 -0.2126 18 1 8.4148 7.6531 0.3332 19 1 7.0124 7.1588 -1.5825 20 1 6.1894 6.7474 0.6612 21 6 9.2164 2.0411 3.0829 22 6 10.0693 0.7782 2.9476 23 6 10.6655 0.7139 1.5400 24 6 11.1991 0.8128 3.9789 25 6 9.1963 -0.4550 3.1886 26 6 5.2124 0.1132 1.1675 27 6 4.2228 0.0467 -0.0005 28 1 -0.3634 -1.0276 -0.0005 29 1 -0.3633 0.5139 0.8900 30 1 -0.3633 0.5139 -0.8899 31 1 4.6275 2.7027 -0.9405 32 1 3.3561 3.3688 0.1142 33 1 5.6600 3.5360 1.1201 34 1 4.5349 2.5735 2.1090 35 1 6.5511 1.4347 0.1171 36 1 9.5768 2.8018 0.6054 37 1 8.0393 2.2091 -0.0678 38 1 8.8219 5.1707 -2.1116 39 1 9.8547 2.9210 3.0022 40 1 8.7185 2.0412 4.0526 41 1 11.2874 1.5924 1.3683 42 1 11.2729 -0.1861 1.4435 43 1 9.8607 0.6892 0.8053 44 1 10.7743 0.8586 4.9817 45 1 11.8064 -0.0871 3.8827 46 1 11.8209 1.6913 3.8071 47 1 8.4423 -0.5253 2.4046 48 1 9.8193 -1.3494 3.1750 49 1 8.7056 -0.3688 4.1581 50 1 4.6650 0.0967 2.1098 51 1 5.8858 -0.7428 1.1228 52 1 3.5758 -0.8225 0.1177 53 1 4.7686 -0.0292 -0.9411 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 ZINC000826578031.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 06:10:38 Heat of formation + Delta-G solvation = -131.138543 kcal Electronic energy + Delta-G solvation = -32524.942480 eV Core-core repulsion = 28396.293628 eV Total energy + Delta-G solvation = -4128.648853 eV No. of doubly occupied orbitals = 66 Molecular weight (most abundant/longest-lived isotopes) = 340.220 amu Computer time = 1.03 seconds Orbital eigenvalues (eV) -40.59156 -39.73081 -37.86757 -36.60854 -35.94497 -34.43902 -32.62023 -32.37652 -30.88373 -27.99757 -27.65208 -26.96670 -26.80028 -26.35747 -24.67342 -23.20724 -22.80409 -21.59486 -19.92567 -18.86820 -18.12111 -17.70079 -16.98914 -16.64533 -16.47322 -16.23786 -15.41799 -15.00047 -14.62690 -14.44397 -14.27405 -14.06835 -14.03550 -13.61234 -13.53801 -13.24066 -12.91044 -12.79619 -12.45784 -12.42081 -12.11092 -12.07837 -11.96382 -11.86126 -11.55247 -11.53757 -11.27484 -11.13069 -11.01900 -10.96427 -10.86908 -10.76783 -10.57894 -10.49858 -10.41277 -10.29953 -10.20502 -10.06612 -9.99926 -9.67408 -8.97871 -8.60156 -8.50480 -7.66194 -6.22743 -4.29368 2.25139 2.91350 3.20141 3.28809 3.30733 3.42546 3.91584 3.98808 4.30046 4.95959 5.05911 5.09139 5.11660 5.14550 5.16725 5.20416 5.21409 5.33572 5.37445 5.38645 5.54710 5.60492 5.74993 5.81486 5.85723 5.90175 5.95181 6.02017 6.04874 6.09828 6.11386 6.17875 6.20912 6.24618 6.29659 6.37452 6.40280 6.45916 6.48969 6.54596 6.63152 6.70166 6.78112 6.84619 6.88076 7.17453 7.45301 7.54805 7.73400 8.03059 8.35253 8.36459 8.76242 9.05831 9.38081 10.83236 Molecular weight = 340.22amu Principal moments of inertia in cm(-1) A = 0.009082 B = 0.004457 C = 0.003226 Principal moments of inertia in units of 10**(-40)*gram-cm**2 A = 3082.263990 B = 6280.694711 C = 8678.433067 Net atomic charges, atomic populations, and dipole contributions calculated with CM2 Atom NO. Type Charge No. of electrons 1 C 0.057 3.943 2 O -0.373 6.373 3 C 0.647 3.353 4 O -0.578 6.578 5 N -0.589 5.589 6 C 0.130 3.870 7 C -0.125 4.125 8 C -0.100 4.100 9 C 0.524 3.476 10 O -0.571 6.571 11 N -0.591 5.591 12 C 0.236 3.764 13 C -0.536 4.536 14 H 0.062 0.938 15 C 0.069 3.931 16 N -0.888 5.888 17 Si 0.888 3.112 18 H -0.280 1.280 19 H -0.285 1.285 20 H -0.271 1.271 21 C 0.130 3.870 22 C -0.085 4.085 23 C -0.137 4.137 24 C -0.136 4.136 25 C -0.127 4.127 26 C -0.116 4.116 27 C 0.114 3.886 28 H 0.099 0.901 29 H 0.061 0.939 30 H 0.061 0.939 31 H 0.080 0.920 32 H 0.094 0.906 33 H 0.115 0.885 34 H 0.061 0.939 35 H 0.100 0.900 36 H 0.041 0.959 37 H 0.036 0.964 38 H 0.265 0.735 39 H 0.074 0.926 40 H 0.069 0.931 41 H 0.055 0.945 42 H 0.043 0.957 43 H 0.062 0.938 44 H 0.052 0.948 45 H 0.051 0.949 46 H 0.054 0.946 47 H 0.052 0.948 48 H 0.039 0.961 49 H 0.057 0.943 50 H 0.075 0.925 51 H 0.074 0.926 52 H 0.089 0.911 53 H 0.072 0.928 For the charges calculated by CM2: Dipole moment (debyes) X Y Z Total from point charges -4.652 -10.414 2.127 11.602 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 -0.038 4.038 2 O -0.287 6.287 3 C 0.402 3.598 4 O -0.468 6.468 5 N -0.329 5.329 6 C 0.009 3.991 7 C -0.163 4.163 8 C -0.122 4.122 9 C 0.312 3.688 10 O -0.452 6.452 11 N -0.320 5.320 12 C 0.116 3.884 13 C -0.575 4.575 14 H 0.080 0.920 15 C -0.134 4.134 16 N -0.526 5.526 17 Si 0.716 3.284 18 H -0.206 1.206 19 H -0.210 1.210 20 H -0.196 1.196 21 C 0.006 3.994 22 C -0.086 4.086 23 C -0.195 4.195 24 C -0.194 4.194 25 C -0.184 4.184 26 C -0.155 4.155 27 C -0.009 4.009 28 H 0.118 0.882 29 H 0.080 0.920 30 H 0.079 0.921 31 H 0.098 0.902 32 H 0.112 0.888 33 H 0.133 0.867 34 H 0.080 0.920 35 H 0.118 0.882 36 H 0.059 0.941 37 H 0.054 0.946 38 H 0.075 0.925 39 H 0.093 0.907 40 H 0.088 0.912 41 H 0.074 0.926 42 H 0.062 0.938 43 H 0.081 0.919 44 H 0.071 0.929 45 H 0.070 0.930 46 H 0.073 0.927 47 H 0.071 0.929 48 H 0.058 0.942 49 H 0.076 0.924 50 H 0.094 0.906 51 H 0.092 0.908 52 H 0.108 0.892 53 H 0.091 0.909 Dipole moment (debyes) X Y Z Total from point charges -4.980 -10.313 2.468 11.715 hybrid contribution -0.309 1.155 -0.197 1.212 sum -5.289 -9.157 2.271 10.816 Atomic orbital electron populations 1.23133 0.74957 1.03105 1.02576 1.86225 1.23748 1.31396 1.87306 1.18050 0.83343 0.81952 0.76499 1.90970 1.64299 1.34892 1.56598 1.47074 1.01596 1.09142 1.75062 1.21753 0.95005 0.82594 0.99721 1.22054 0.96478 1.00146 0.97663 1.21259 0.95585 0.95814 0.99501 1.20285 0.82314 0.77484 0.88690 1.90580 1.78181 1.48845 1.27627 1.48176 1.13651 1.52236 1.17944 1.19520 0.97832 0.91454 0.79562 1.21481 1.37078 0.97722 1.01183 0.92014 1.24887 0.94966 0.98384 0.95188 1.69910 1.41272 1.36548 1.04874 0.86641 0.79655 0.84584 0.77561 1.20585 1.21032 1.19552 1.21348 0.90128 0.96386 0.91556 1.20971 0.95416 0.96467 0.95775 1.21899 1.00711 1.00737 0.96116 1.21790 0.97718 1.01392 0.98503 1.21793 0.98610 0.95723 1.02259 1.21789 0.97622 0.97314 0.98773 1.21772 0.93688 0.86271 0.99151 0.88246 0.92025 0.92053 0.90169 0.88767 0.86694 0.92033 0.88225 0.94130 0.94640 0.92514 0.90742 0.91220 0.92626 0.93779 0.91875 0.92895 0.92960 0.92700 0.92902 0.94188 0.92400 0.90628 0.90762 0.89215 0.90942 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 0.06 0.56 10.56 101.05 1.07 1.62 16 2 O -0.37 -4.98 9.20 -40.30 -0.37 -5.35 16 3 C 0.65 10.40 8.43 54.06 0.46 10.86 16 4 O -0.58 -10.82 15.54 -19.27 -0.30 -11.12 16 5 N -0.59 -8.94 2.97 -178.54 -0.53 -9.48 16 6 C 0.13 2.10 6.42 -3.71 -0.02 2.07 16 7 C -0.13 -2.18 5.36 -26.45 -0.14 -2.32 16 8 C -0.10 -1.70 1.90 -91.57 -0.17 -1.88 16 9 C 0.52 10.01 5.13 -10.98 -0.06 9.96 16 10 O -0.57 -11.87 13.97 5.56 0.08 -11.79 16 11 N -0.59 -11.35 1.94 -175.07 -0.34 -11.69 16 12 C 0.24 5.07 3.60 -5.20 -0.02 5.05 16 13 C -0.54 -12.73 7.41 -34.44 -0.26 -12.98 16 14 H 0.06 1.51 7.33 -52.48 -0.38 1.13 16 15 C 0.07 1.71 5.46 -17.82 -0.10 1.61 16 16 N -0.89 -22.94 13.29 55.43 0.74 -22.20 16 17 Si 0.89 19.66 29.54 -169.99 -5.02 14.64 16 18 H -0.28 -6.26 7.11 56.52 0.40 -5.86 16 19 H -0.28 -6.34 7.11 56.52 0.40 -5.93 16 20 H -0.27 -5.96 7.11 56.52 0.40 -5.56 16 21 C 0.13 2.27 4.58 -4.04 -0.02 2.25 16 22 C -0.09 -1.28 0.85 -154.50 -0.13 -1.41 16 23 C -0.14 -2.08 7.20 37.16 0.27 -1.82 16 24 C -0.14 -1.72 8.47 37.16 0.31 -1.41 16 25 C -0.13 -1.94 7.10 37.16 0.26 -1.67 16 26 C -0.12 -1.68 4.96 -26.59 -0.13 -1.82 16 27 C 0.11 1.46 6.45 -3.69 -0.02 1.44 16 28 H 0.10 0.63 8.14 -51.93 -0.42 0.21 16 29 H 0.06 0.61 8.14 -51.93 -0.42 0.19 16 30 H 0.06 0.59 8.14 -51.93 -0.42 0.17 16 31 H 0.08 1.27 8.14 -51.93 -0.42 0.85 16 32 H 0.09 1.59 7.00 -51.93 -0.36 1.22 16 33 H 0.12 2.26 5.49 -51.93 -0.28 1.98 16 34 H 0.06 1.11 8.14 -51.93 -0.42 0.69 16 35 H 0.10 1.75 5.90 -51.93 -0.31 1.44 16 36 H 0.04 0.93 6.58 -51.93 -0.34 0.58 16 37 H 0.04 0.79 5.94 -51.93 -0.31 0.48 16 38 H 0.27 6.62 8.31 -40.82 -0.34 6.28 16 39 H 0.07 1.32 8.05 -51.93 -0.42 0.90 16 40 H 0.07 1.27 7.44 -51.93 -0.39 0.88 16 41 H 0.05 0.86 7.87 -51.93 -0.41 0.45 16 42 H 0.04 0.59 8.14 -51.93 -0.42 0.17 16 43 H 0.06 1.06 6.35 -51.93 -0.33 0.73 16 44 H 0.05 0.64 8.14 -51.93 -0.42 0.22 16 45 H 0.05 0.60 8.14 -51.93 -0.42 0.18 16 46 H 0.05 0.67 8.14 -51.93 -0.42 0.24 16 47 H 0.05 0.89 6.35 -51.93 -0.33 0.56 16 48 H 0.04 0.54 8.14 -51.93 -0.42 0.11 16 49 H 0.06 0.94 7.75 -51.93 -0.40 0.54 16 50 H 0.08 1.20 7.90 -51.93 -0.41 0.79 16 51 H 0.07 1.00 8.14 -51.93 -0.42 0.58 16 52 H 0.09 1.03 6.93 -51.93 -0.36 0.67 16 53 H 0.07 0.85 8.14 -51.93 -0.42 0.43 16 LS Contribution 404.54 15.07 6.10 6.10 Total: -1.00 -28.41 404.54 -7.60 -36.01 By element: Atomic # 1 Polarization: 14.57 SS G_CDS: -9.24 Total: 5.33 kcal Atomic # 6 Polarization: 8.26 SS G_CDS: 1.30 Total: 9.55 kcal Atomic # 7 Polarization: -43.23 SS G_CDS: -0.13 Total: -43.37 kcal Atomic # 8 Polarization: -27.67 SS G_CDS: -0.59 Total: -28.26 kcal Atomic # 14 Polarization: 19.66 SS G_CDS: -5.02 Total: 14.64 kcal Total LS contribution 6.10 Total: 6.10 kcal Total: -28.41 -7.60 -36.01 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. ZINC000826578031.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 -95.131 kcal (2) G-P(sol) polarization free energy of solvation -28.411 kcal (3) G-ENP(sol) elect.-nuc.-pol. free energy of system -123.542 kcal (4) G-CDS(sol) cavity-dispersion-solvent structure free energy -7.597 kcal (5) G-P-CDS(sol) = G-P(sol) + G-CDS(sol) = (2) + (4) -36.008 kcal (6) G-S(sol) free energy of system = (1) + (5) -131.139 kcal 1SCF WAS SPECIFIED, SO GEOMETRY OPTIMIZATION WAS NOT USED Total computer time = 1.03 seconds