Wall clock time and date at job start Sat Apr 11 2020 06:11:02 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 1.53000 * 1 3 3 C 1.53007 * 109.46703 * 2 1 4 4 C 1.53007 * 109.46982 * 180.02562 * 3 2 1 5 5 O 1.42896 * 109.47277 * 179.97438 * 4 3 2 6 6 C 1.42894 * 114.00047 * 179.97438 * 5 4 3 7 7 H 1.08992 * 109.47566 * 330.00316 * 6 5 4 8 8 C 1.53002 * 109.46680 * 90.00608 * 6 5 4 9 9 C 1.50702 * 109.47318 * 210.00103 * 6 5 4 10 10 O 1.21287 * 119.99844 * 346.06090 * 9 6 5 11 11 N 1.34777 * 120.00111 * 166.05558 * 9 6 5 12 12 C 1.47480 * 125.66313 * 184.24299 * 11 9 6 13 13 C 1.55257 * 104.78182 * 155.91431 * 12 11 9 14 14 C 1.54515 * 101.42665 * 36.67708 * 13 12 11 15 15 C 1.47184 * 125.65878 * 4.55115 * 11 9 6 16 16 C 1.52517 * 110.05537 * 206.73766 * 14 13 12 17 17 N 1.47301 * 108.41374 * 287.84988 * 16 14 13 18 18 C 1.36940 * 121.06107 * 130.60741 * 17 16 14 19 19 H 1.07994 * 119.99850 * 325.16326 * 18 17 16 20 20 C 1.38814 * 119.99889 * 145.15790 * 18 17 16 21 21 N 1.31617 * 119.99970 * 169.83003 * 20 18 17 22 22 Si 1.86803 * 119.99944 * 349.83382 * 20 18 17 23 23 H 1.48500 * 109.47474 * 84.85185 * 22 20 18 24 24 H 1.48500 * 109.46911 * 204.84854 * 22 20 18 25 25 H 1.48501 * 109.47131 * 324.84753 * 22 20 18 26 26 C 1.47162 * 117.87891 * 310.63860 * 17 16 14 27 27 C 1.53283 * 108.54025 * 51.13137 * 26 17 16 28 28 O 1.42069 * 110.33441 * 83.75127 * 14 13 12 29 29 H 1.09005 * 109.46857 * 299.99808 * 1 2 3 30 30 H 1.09001 * 109.47542 * 60.00337 * 1 2 3 31 31 H 1.09004 * 109.46938 * 180.02562 * 1 2 3 32 32 H 1.08995 * 109.47270 * 240.00521 * 2 1 3 33 33 H 1.09001 * 109.47542 * 119.99662 * 2 1 3 34 34 H 1.09001 * 109.46846 * 300.00088 * 3 2 1 35 35 H 1.08996 * 109.47340 * 60.00395 * 3 2 1 36 36 H 1.09003 * 109.46951 * 300.00046 * 4 3 2 37 37 H 1.09005 * 109.46760 * 60.00080 * 4 3 2 38 38 H 1.08994 * 109.47167 * 307.15227 * 8 6 5 39 39 H 1.09000 * 109.47257 * 67.15992 * 8 6 5 40 40 H 1.09005 * 109.47256 * 187.15458 * 8 6 5 41 41 H 1.08997 * 110.35553 * 274.86927 * 12 11 9 42 42 H 1.09002 * 110.35269 * 37.15556 * 12 11 9 43 43 H 1.09003 * 111.21560 * 278.58740 * 13 12 11 44 44 H 1.08998 * 110.90745 * 154.63749 * 13 12 11 45 45 H 1.08999 * 109.91087 * 300.84011 * 15 11 9 46 46 H 1.08994 * 109.91015 * 61.92551 * 15 11 9 47 47 H 1.08997 * 109.67687 * 47.58531 * 16 14 13 48 48 H 1.09007 * 109.67408 * 168.12621 * 16 14 13 49 49 H 0.97000 * 119.99747 * 180.02562 * 21 20 18 50 50 H 1.09000 * 109.62223 * 291.41477 * 26 17 16 51 51 H 1.09001 * 109.78511 * 170.94350 * 26 17 16 52 52 H 1.09008 * 109.51258 * 187.16083 * 27 26 17 53 53 H 1.08997 * 109.51513 * 67.01171 * 27 26 17 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 6 2.0399 1.4426 0.0000 4 6 3.5700 1.4427 -0.0006 5 8 4.0463 2.7899 -0.0012 6 6 5.4707 2.9028 -0.0013 7 1 5.9033 2.0446 0.5128 8 6 5.9790 2.9426 -1.4439 9 6 5.8744 4.1694 0.7086 10 8 5.0454 5.0226 0.9449 11 7 7.1565 4.3540 1.0809 12 6 7.6705 5.4986 1.8559 13 6 8.9630 4.9695 2.5341 14 6 9.5315 4.0477 1.4320 15 6 8.2771 3.4498 0.7762 16 6 10.3843 2.9489 2.0577 17 7 11.6384 3.5516 2.5411 18 6 12.0940 3.3126 3.8101 19 1 11.3923 3.1949 4.6225 20 6 13.4579 3.2214 4.0523 21 7 13.9061 3.1927 5.2894 22 14 14.6569 3.1395 2.6222 23 1 14.9720 4.5154 2.1609 24 1 15.9057 2.4665 3.0613 25 1 14.0463 2.3714 1.5076 26 6 12.3858 4.4194 1.6169 27 6 11.4233 5.4669 1.0460 28 8 10.2813 4.8055 0.4928 29 1 -0.3633 0.5138 0.8901 30 1 -0.3634 0.5138 -0.8900 31 1 -0.3633 -1.0277 0.0005 32 1 1.8933 -0.5137 -0.8900 33 1 1.8934 -0.5138 0.8900 34 1 1.6765 1.9564 -0.8900 35 1 1.6766 1.9564 0.8900 36 1 3.9337 0.9287 0.8891 37 1 3.9329 0.9290 -0.8909 38 1 5.5811 2.0893 -1.9930 39 1 5.6500 3.8664 -1.9197 40 1 7.0683 2.9005 -1.4466 41 1 7.9013 6.3324 1.1929 42 1 6.9444 5.8026 2.6099 43 1 8.7316 4.4032 3.4363 44 1 9.6500 5.7868 2.7529 45 1 8.0786 2.4605 1.1884 46 1 8.4159 3.3812 -0.3027 47 1 9.8478 2.4985 2.8928 48 1 10.6074 2.1872 1.3105 49 1 14.8591 3.1293 5.4586 50 1 12.7985 3.8203 0.8052 51 1 13.1944 4.9180 2.1515 52 1 11.9271 6.0373 0.2656 53 1 11.1042 6.1401 1.8416 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 ZINC001755400890.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 06:11:02 Heat of formation + Delta-G solvation = -98.449559 kcal Electronic energy + Delta-G solvation = -31179.755170 eV Core-core repulsion = 27052.523818 eV Total energy + Delta-G solvation = -4127.231352 eV No. of doubly occupied orbitals = 66 Molecular weight (most abundant/longest-lived isotopes) = 340.220 amu Computer time = 0.91 seconds Orbital eigenvalues (eV) -40.62033 -39.36815 -37.98192 -36.29415 -35.32477 -34.70081 -32.43004 -31.73118 -31.23291 -29.80112 -29.06723 -27.84818 -26.15059 -24.91976 -23.69141 -23.30190 -22.32584 -21.70720 -21.48105 -19.53529 -19.17950 -17.47130 -17.16811 -16.81747 -16.60790 -16.25185 -15.76153 -15.39682 -15.30963 -14.86571 -14.61188 -14.28092 -14.18911 -14.16380 -13.77927 -13.69342 -13.50186 -13.20290 -12.75942 -12.64572 -12.59197 -12.50046 -12.45750 -12.31842 -12.01280 -11.89124 -11.64270 -11.58052 -11.43613 -11.21570 -11.19717 -11.07626 -10.99412 -10.82367 -10.48597 -10.38511 -10.11033 -9.77099 -9.67382 -9.58120 -9.36680 -8.68908 -8.66137 -7.00182 -6.06394 -3.55622 2.53955 2.60610 3.20052 3.37762 3.39890 3.54996 3.87601 4.27455 4.39500 4.51758 4.55156 4.59552 4.69759 4.72817 4.79946 4.82707 4.94893 4.96613 5.05736 5.09043 5.21946 5.22862 5.24367 5.35817 5.39965 5.46189 5.48252 5.48837 5.53104 5.57046 5.58578 5.69034 5.76057 5.81623 5.86367 5.87910 5.90367 5.96091 6.00517 6.07801 6.12372 6.23011 6.31863 6.36648 6.38769 6.59015 6.86682 7.44529 7.56216 7.84641 8.12302 8.20555 8.75414 9.55545 9.94205 11.08882 Molecular weight = 340.22amu Principal moments of inertia in cm(-1) A = 0.019125 B = 0.002333 C = 0.002239 Principal moments of inertia in units of 10**(-40)*gram-cm**2 A = 1463.676802 B =11996.910764 C =12503.954164 Net atomic charges, atomic populations, and dipole contributions calculated with CM2 Atom NO. Type Charge No. of electrons 1 C -0.152 4.152 2 C -0.122 4.122 3 C -0.119 4.119 4 C 0.058 3.942 5 O -0.359 6.359 6 C 0.076 3.924 7 H 0.084 0.916 8 C -0.172 4.172 9 C 0.532 3.468 10 O -0.524 6.524 11 N -0.613 5.613 12 C 0.112 3.888 13 C -0.146 4.146 14 C 0.093 3.907 15 C 0.112 3.888 16 C 0.134 3.866 17 N -0.605 5.605 18 C -0.264 4.264 19 H 0.085 0.915 20 C 0.028 3.972 21 N -0.910 5.910 22 Si 0.895 3.105 23 H -0.286 1.286 24 H -0.303 1.303 25 H -0.271 1.271 26 C 0.085 3.915 27 C 0.046 3.954 28 O -0.372 6.372 29 H 0.055 0.945 30 H 0.055 0.945 31 H 0.055 0.945 32 H 0.063 0.937 33 H 0.064 0.936 34 H 0.071 0.929 35 H 0.072 0.928 36 H 0.051 0.949 37 H 0.050 0.950 38 H 0.070 0.930 39 H 0.069 0.931 40 H 0.076 0.924 41 H 0.069 0.931 42 H 0.076 0.924 43 H 0.087 0.913 44 H 0.094 0.906 45 H 0.084 0.916 46 H 0.082 0.918 47 H 0.075 0.925 48 H 0.033 0.967 49 H 0.265 0.735 50 H 0.035 0.965 51 H 0.082 0.918 52 H 0.088 0.912 53 H 0.056 0.944 For the charges calculated by CM2: Dipole moment (debyes) X Y Z Total from point charges -17.818 -3.715 -12.692 22.189 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 -0.209 4.209 2 C -0.160 4.160 3 C -0.156 4.156 4 C -0.019 4.019 5 O -0.277 6.277 6 C 0.015 3.985 7 H 0.102 0.898 8 C -0.229 4.229 9 C 0.319 3.681 10 O -0.399 6.399 11 N -0.349 5.349 12 C -0.010 4.010 13 C -0.184 4.184 14 C 0.051 3.949 15 C -0.012 4.012 16 C 0.008 3.992 17 N -0.330 5.330 18 C -0.393 4.393 19 H 0.103 0.897 20 C -0.172 4.172 21 N -0.552 5.552 22 Si 0.726 3.274 23 H -0.213 1.213 24 H -0.231 1.231 25 H -0.196 1.196 26 C -0.040 4.040 27 C -0.032 4.032 28 O -0.291 6.291 29 H 0.075 0.925 30 H 0.074 0.926 31 H 0.074 0.926 32 H 0.082 0.918 33 H 0.082 0.918 34 H 0.090 0.910 35 H 0.091 0.909 36 H 0.069 0.931 37 H 0.069 0.931 38 H 0.089 0.911 39 H 0.088 0.912 40 H 0.095 0.905 41 H 0.087 0.913 42 H 0.094 0.906 43 H 0.105 0.895 44 H 0.112 0.888 45 H 0.102 0.898 46 H 0.100 0.900 47 H 0.093 0.907 48 H 0.051 0.949 49 H 0.075 0.925 50 H 0.053 0.947 51 H 0.100 0.900 52 H 0.106 0.894 53 H 0.074 0.926 Dipole moment (debyes) X Y Z Total from point charges -18.388 -3.126 -12.635 22.528 hybrid contribution 1.283 -0.278 -0.462 1.392 sum -17.105 -3.404 -13.097 21.810 Atomic orbital electron populations 1.21754 0.95377 1.01709 1.02090 1.21448 0.96302 0.95968 1.02252 1.21542 0.93172 0.97244 1.03663 1.22667 0.95442 0.83503 1.00252 1.88024 1.18445 1.26243 1.94981 1.21823 0.83480 0.96331 0.96874 0.89785 1.22257 1.02133 1.03796 0.94759 1.19964 0.80716 0.88338 0.79095 1.90711 1.49794 1.44607 1.54837 1.48494 1.06590 1.24831 1.55031 1.22336 0.95491 0.88642 0.94548 1.23278 0.95724 1.01047 0.98357 1.22279 0.90389 0.93239 0.88983 1.22022 0.84607 0.93274 1.01249 1.21403 0.88048 0.92283 0.97489 1.44280 1.23687 1.52593 1.12442 1.18829 0.91653 1.45748 0.83023 0.89707 1.25457 0.97386 0.98267 0.96051 1.69745 1.14199 1.52809 1.18427 0.86831 0.80276 0.77428 0.82845 1.21323 1.23092 1.19586 1.22118 0.95297 0.92615 0.93988 1.23161 0.86795 0.94915 0.98309 1.87684 1.40415 1.66149 1.34887 0.92548 0.92610 0.92608 0.91835 0.91755 0.91026 0.90921 0.93123 0.93131 0.91086 0.91174 0.90489 0.91309 0.90555 0.89464 0.88780 0.89839 0.89963 0.90652 0.94905 0.92534 0.94706 0.89976 0.89424 0.92558 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 -0.88 9.91 37.16 0.37 -0.51 16 2 C -0.12 -0.76 5.93 -26.73 -0.16 -0.92 16 3 C -0.12 -0.96 5.58 -26.72 -0.15 -1.11 16 4 C 0.06 0.52 5.75 37.16 0.21 0.73 16 5 O -0.36 -4.54 9.56 -54.74 -0.52 -5.06 16 6 C 0.08 0.87 2.53 -27.88 -0.07 0.80 16 7 H 0.08 0.78 7.41 -51.93 -0.38 0.40 16 8 C -0.17 -1.61 9.39 37.16 0.35 -1.26 16 9 C 0.53 7.87 7.15 -10.98 -0.08 7.79 16 10 O -0.52 -9.83 16.85 -13.96 -0.24 -10.07 16 11 N -0.61 -8.43 3.33 -170.54 -0.57 -9.00 16 12 C 0.11 1.57 6.90 -2.31 -0.02 1.56 16 13 C -0.15 -2.16 5.93 -24.74 -0.15 -2.31 16 14 C 0.09 1.41 0.83 -89.73 -0.07 1.34 16 15 C 0.11 1.38 5.44 -3.32 -0.02 1.37 16 16 C 0.13 2.39 5.27 -3.85 -0.02 2.37 16 17 N -0.60 -13.22 2.65 -172.18 -0.46 -13.67 16 18 C -0.26 -6.90 10.10 -15.06 -0.15 -7.05 16 19 H 0.09 2.38 8.06 -52.49 -0.42 1.96 16 20 C 0.03 0.78 5.37 -17.43 -0.09 0.69 16 21 N -0.91 -26.77 13.97 55.49 0.78 -25.99 16 22 Si 0.90 21.48 24.25 -169.99 -4.12 17.36 16 23 H -0.29 -6.52 6.45 56.52 0.36 -6.16 16 24 H -0.30 -7.46 7.11 56.52 0.40 -7.06 16 25 H -0.27 -6.41 6.55 56.52 0.37 -6.04 16 26 C 0.09 1.72 4.33 -3.53 -0.02 1.70 16 27 C 0.05 0.76 6.76 37.30 0.25 1.01 16 28 O -0.37 -6.09 10.22 -35.23 -0.36 -6.45 16 29 H 0.06 0.33 8.14 -51.93 -0.42 -0.09 16 30 H 0.05 0.31 8.14 -51.93 -0.42 -0.11 16 31 H 0.05 0.28 8.14 -51.93 -0.42 -0.14 16 32 H 0.06 0.36 8.14 -51.93 -0.42 -0.07 16 33 H 0.06 0.39 8.14 -51.93 -0.42 -0.04 16 34 H 0.07 0.59 8.14 -51.93 -0.42 0.17 16 35 H 0.07 0.65 8.14 -51.93 -0.42 0.23 16 36 H 0.05 0.42 8.09 -51.93 -0.42 0.00 16 37 H 0.05 0.37 7.76 -51.93 -0.40 -0.03 16 38 H 0.07 0.54 7.75 -51.93 -0.40 0.14 16 39 H 0.07 0.74 8.13 -51.93 -0.42 0.32 16 40 H 0.08 0.65 5.88 -51.93 -0.31 0.35 16 41 H 0.07 0.97 8.14 -51.93 -0.42 0.55 16 42 H 0.08 1.08 8.08 -51.93 -0.42 0.66 16 43 H 0.09 1.32 7.86 -51.93 -0.41 0.92 16 44 H 0.09 1.47 5.98 -51.93 -0.31 1.16 16 45 H 0.08 0.88 7.54 -51.93 -0.39 0.48 16 46 H 0.08 0.94 6.18 -51.93 -0.32 0.62 16 47 H 0.08 1.31 7.75 -51.93 -0.40 0.91 16 48 H 0.03 0.57 8.14 -51.92 -0.42 0.15 16 49 H 0.26 7.43 8.31 -40.82 -0.34 7.09 16 50 H 0.04 0.72 6.72 -51.93 -0.35 0.37 16 51 H 0.08 1.78 4.88 -51.93 -0.25 1.53 16 52 H 0.09 1.23 8.14 -51.92 -0.42 0.81 16 53 H 0.06 0.92 6.14 -51.93 -0.32 0.60 16 LS Contribution 402.06 15.07 6.06 6.06 Total: -1.00 -32.36 402.06 -8.61 -40.97 By element: Atomic # 1 Polarization: 9.04 SS G_CDS: -9.37 Total: -0.32 kcal Atomic # 6 Polarization: 5.99 SS G_CDS: 0.19 Total: 6.18 kcal Atomic # 7 Polarization: -48.41 SS G_CDS: -0.25 Total: -48.66 kcal Atomic # 8 Polarization: -20.46 SS G_CDS: -1.12 Total: -21.58 kcal Atomic # 14 Polarization: 21.48 SS G_CDS: -4.12 Total: 17.36 kcal Total LS contribution 6.06 Total: 6.06 kcal Total: -32.36 -8.61 -40.97 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. ZINC001755400890.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 -57.483 kcal (2) G-P(sol) polarization free energy of solvation -32.359 kcal (3) G-ENP(sol) elect.-nuc.-pol. free energy of system -89.842 kcal (4) G-CDS(sol) cavity-dispersion-solvent structure free energy -8.607 kcal (5) G-P-CDS(sol) = G-P(sol) + G-CDS(sol) = (2) + (4) -40.966 kcal (6) G-S(sol) free energy of system = (1) + (5) -98.450 kcal 1SCF WAS SPECIFIED, SO GEOMETRY OPTIMIZATION WAS NOT USED Total computer time = 0.91 seconds