Wall clock time and date at job start Tue Mar 31 2020 23:55:07 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 1.42902 * 1 3 3 C 1.42895 * 113.99804 * 2 1 4 4 C 1.53003 * 109.47152 * 180.02562 * 3 2 1 5 5 C 1.53004 * 109.47437 * 184.39933 * 4 3 2 6 6 N 1.46497 * 109.45511 * 303.07418 * 5 4 3 7 7 C 1.34778 * 120.00630 * 303.02632 * 6 5 4 8 8 O 1.21284 * 119.99576 * 355.03007 * 7 6 5 9 9 C 1.50690 * 120.00742 * 175.02864 * 7 6 5 10 10 H 1.09006 * 110.80395 * 300.70579 * 9 7 6 11 11 C 1.54997 * 110.93904 * 64.34645 * 9 7 6 12 12 O 1.44374 * 103.49479 * 155.23883 * 11 9 7 13 13 C 1.43752 * 106.97343 * 319.94211 * 12 11 9 14 14 H 1.09005 * 109.87772 * 267.09047 * 13 12 11 15 15 C 1.53001 * 110.00598 * 146.00602 * 13 12 11 16 16 C 1.54094 * 107.29303 * 26.51183 * 13 12 11 17 17 C 1.53040 * 109.44849 * 63.03900 * 5 4 3 18 18 C 1.53195 * 109.30877 * 181.38140 * 17 5 4 19 19 N 1.46928 * 108.77390 * 305.36524 * 18 17 5 20 20 C 1.36939 * 120.62809 * 233.58806 * 19 18 17 21 21 H 1.07994 * 120.00109 * 31.79241 * 20 19 18 22 22 C 1.38814 * 119.99758 * 211.80141 * 20 19 18 23 23 N 1.31622 * 120.00049 * 10.82690 * 22 20 19 24 24 Si 1.86808 * 119.99890 * 190.83612 * 22 20 19 25 25 H 1.48491 * 109.47002 * 89.99322 * 24 22 20 26 26 H 1.48493 * 109.46933 * 209.99398 * 24 22 20 27 27 H 1.48502 * 109.46796 * 329.99338 * 24 22 20 28 28 C 1.46921 * 118.74087 * 53.61211 * 19 18 17 29 29 C 1.53041 * 109.45986 * 183.10493 * 5 4 3 30 30 H 1.09001 * 109.47101 * 179.97438 * 1 2 3 31 31 H 1.08992 * 109.47091 * 300.00197 * 1 2 3 32 32 H 1.09001 * 109.47115 * 60.00402 * 1 2 3 33 33 H 1.09001 * 109.47453 * 59.99842 * 3 2 1 34 34 H 1.09000 * 109.47211 * 299.99625 * 3 2 1 35 35 H 1.08995 * 109.47361 * 64.38913 * 4 3 2 36 36 H 1.09007 * 109.46896 * 304.39638 * 4 3 2 37 37 H 0.97001 * 119.99904 * 123.02617 * 6 5 4 38 38 H 1.09005 * 110.62280 * 273.74064 * 11 9 7 39 39 H 1.09003 * 110.61395 * 36.73704 * 11 9 7 40 40 H 1.09003 * 109.46904 * 302.10046 * 15 13 12 41 41 H 1.09000 * 109.46805 * 62.09197 * 15 13 12 42 42 H 1.08998 * 109.47315 * 182.09187 * 15 13 12 43 43 H 1.09005 * 110.49190 * 239.29392 * 16 13 12 44 44 H 1.09003 * 110.60403 * 116.70036 * 16 13 12 45 45 H 1.08996 * 109.50031 * 301.33202 * 17 5 4 46 46 H 1.09000 * 109.49926 * 61.43300 * 17 5 4 47 47 H 1.08997 * 109.58420 * 185.57873 * 18 17 5 48 48 H 1.08998 * 109.70445 * 65.22744 * 18 17 5 49 49 H 0.96999 * 119.99844 * 180.02562 * 23 22 20 50 50 H 1.09000 * 109.58954 * 186.60238 * 28 19 18 51 51 H 1.09005 * 109.70482 * 66.24239 * 28 19 18 52 52 H 1.09001 * 109.49794 * 298.57391 * 29 5 4 53 53 H 1.09003 * 109.49840 * 58.67380 * 29 5 4 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 2.0102 1.3054 0.0000 4 6 3.5354 1.1847 -0.0006 5 6 4.1575 2.5782 0.1100 6 7 3.6737 3.4172 -0.9892 7 6 3.8548 3.0256 -2.2660 8 8 4.4965 2.0253 -2.5083 9 6 3.2601 3.8305 -3.3927 10 1 2.1763 3.8925 -3.2941 11 6 3.8913 5.2447 -3.4563 12 8 3.7068 5.6343 -4.8343 13 6 3.9626 4.4698 -5.6374 14 1 5.0076 4.4552 -5.9469 15 6 3.0553 4.4740 -6.8694 16 6 3.6570 3.2362 -4.7659 17 6 3.7597 3.2091 1.4463 18 6 4.3555 4.6174 1.5389 19 7 5.8059 4.5325 1.3196 20 6 6.6811 5.0672 2.2269 21 1 6.4266 5.0860 3.2763 22 6 7.8954 5.5852 1.7978 23 7 8.1193 5.7593 0.5125 24 14 9.2119 6.0348 3.0446 25 1 10.0835 4.8580 3.2902 26 1 10.0308 7.1557 2.5172 27 1 8.5679 6.4482 4.3172 28 6 6.2992 3.8636 0.1081 29 6 5.6816 2.4639 0.0315 30 1 -0.3633 -1.0277 -0.0005 31 1 -0.3633 0.5138 0.8899 32 1 -0.3633 0.5138 -0.8900 33 1 1.6885 1.8464 0.8900 34 1 1.6886 1.8463 -0.8900 35 1 3.8622 0.7134 -0.9275 36 1 3.8521 0.5771 0.8472 37 1 3.2230 4.2546 -0.7980 38 1 3.3665 5.9297 -2.7903 39 1 4.9518 5.2032 -3.2079 40 1 2.0128 4.5067 -6.5527 41 1 3.2769 5.3488 -7.4807 42 1 3.2299 3.5697 -7.4523 43 1 4.5432 2.6089 -4.6684 44 1 2.8304 2.6641 -5.1873 45 1 2.6733 3.2688 1.5114 46 1 4.1407 2.5984 2.2648 47 1 4.1591 5.0330 2.5272 48 1 3.9077 5.2567 0.7781 49 1 8.9679 6.1210 0.2127 50 1 7.3853 3.7819 0.1523 51 1 6.0116 4.4386 -0.7722 52 1 6.0445 1.8601 0.8633 53 1 5.9631 1.9930 -0.9105 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 ZINC001151198734.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 23:55:07 Heat of formation + Delta-G solvation = -111.413857 kcal Electronic energy + Delta-G solvation = -32604.144834 eV Core-core repulsion = 28476.351308 eV Total energy + Delta-G solvation = -4127.793526 eV No. of doubly occupied orbitals = 66 Molecular weight (most abundant/longest-lived isotopes) = 340.220 amu Computer time = 1.51 seconds Orbital eigenvalues (eV) -40.68623 -39.30703 -37.79300 -37.20378 -34.58428 -32.65966 -32.29903 -31.59779 -30.98600 -30.11605 -28.87813 -26.58412 -26.01178 -24.89383 -23.57996 -23.16526 -22.09924 -21.35468 -20.53121 -19.93258 -18.71027 -17.64405 -16.89827 -16.47911 -16.11992 -15.91951 -15.46603 -15.32056 -15.07357 -14.90341 -14.57095 -14.32465 -13.92719 -13.72419 -13.46714 -13.44985 -13.12979 -13.02956 -12.74097 -12.55319 -12.45737 -12.28217 -12.06802 -11.70130 -11.56042 -11.45080 -11.31748 -11.10529 -11.06763 -10.93456 -10.85565 -10.77941 -10.74838 -10.37978 -10.28283 -10.01444 -9.78749 -9.76921 -9.72861 -9.47563 -9.10784 -8.64163 -8.48532 -6.63324 -5.79761 -3.28780 2.83511 3.32755 3.36410 3.43202 3.43987 3.75422 3.85544 4.35195 4.46926 4.66801 4.81996 4.92387 5.02824 5.07015 5.13466 5.14950 5.20967 5.24500 5.31386 5.33206 5.38214 5.43774 5.47359 5.51762 5.55260 5.59850 5.63366 5.67198 5.75573 5.88028 5.89523 5.97401 5.99324 6.07475 6.10346 6.15619 6.33162 6.37948 6.47794 6.62567 6.66856 6.77401 6.83471 6.87125 7.03258 7.15850 7.39682 7.70368 7.77836 7.82503 8.46175 8.48917 9.20875 9.81871 10.39750 11.27677 Molecular weight = 340.22amu Principal moments of inertia in cm(-1) A = 0.008380 B = 0.004418 C = 0.003115 Principal moments of inertia in units of 10**(-40)*gram-cm**2 A = 3340.681630 B = 6336.271728 C = 8987.916893 Net atomic charges, atomic populations, and dipole contributions calculated with CM2 Atom NO. Type Charge No. of electrons 1 C 0.033 3.967 2 O -0.393 6.393 3 C 0.066 3.934 4 C -0.129 4.129 5 C 0.194 3.806 6 N -0.710 5.710 7 C 0.526 3.474 8 O -0.531 6.531 9 C -0.146 4.146 10 H 0.105 0.895 11 C 0.061 3.939 12 O -0.372 6.372 13 C 0.070 3.930 14 H 0.070 0.930 15 C -0.149 4.149 16 C -0.135 4.135 17 C -0.141 4.141 18 C 0.146 3.854 19 N -0.590 5.590 20 C -0.256 4.256 21 H 0.063 0.937 22 C 0.007 3.993 23 N -0.902 5.902 24 Si 0.903 3.097 25 H -0.287 1.287 26 H -0.291 1.291 27 H -0.279 1.279 28 C 0.181 3.819 29 C -0.150 4.150 30 H 0.082 0.918 31 H 0.039 0.961 32 H 0.037 0.963 33 H 0.049 0.951 34 H 0.042 0.958 35 H 0.089 0.911 36 H 0.075 0.925 37 H 0.398 0.602 38 H 0.099 0.901 39 H 0.074 0.926 40 H 0.061 0.939 41 H 0.061 0.939 42 H 0.068 0.932 43 H 0.096 0.904 44 H 0.079 0.921 45 H 0.056 0.944 46 H 0.076 0.924 47 H 0.056 0.944 48 H 0.013 0.987 49 H 0.254 0.746 50 H 0.084 0.916 51 H 0.017 0.983 52 H 0.060 0.940 53 H 0.072 0.928 For the charges calculated by CM2: Dipole moment (debyes) X Y Z Total from point charges -15.130 -5.720 -7.924 18.012 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 -0.064 4.064 2 O -0.312 6.312 3 C -0.010 4.010 4 C -0.168 4.168 5 C 0.109 3.891 6 N -0.362 5.362 7 C 0.312 3.688 8 O -0.408 6.408 9 C -0.168 4.168 10 H 0.123 0.877 11 C -0.016 4.016 12 O -0.291 6.291 13 C 0.012 3.988 14 H 0.088 0.912 15 C -0.206 4.206 16 C -0.173 4.173 17 C -0.180 4.180 18 C 0.019 3.981 19 N -0.313 5.313 20 C -0.386 4.386 21 H 0.081 0.919 22 C -0.192 4.192 23 N -0.546 5.546 24 Si 0.733 3.267 25 H -0.214 1.214 26 H -0.217 1.217 27 H -0.204 1.204 28 C 0.055 3.945 29 C -0.190 4.190 30 H 0.101 0.899 31 H 0.057 0.943 32 H 0.056 0.944 33 H 0.068 0.932 34 H 0.061 0.939 35 H 0.108 0.892 36 H 0.094 0.906 37 H 0.233 0.767 38 H 0.117 0.883 39 H 0.092 0.908 40 H 0.080 0.920 41 H 0.080 0.920 42 H 0.087 0.913 43 H 0.115 0.885 44 H 0.097 0.903 45 H 0.075 0.925 46 H 0.095 0.905 47 H 0.074 0.926 48 H 0.031 0.969 49 H 0.064 0.936 50 H 0.102 0.898 51 H 0.035 0.965 52 H 0.079 0.921 53 H 0.090 0.910 Dipole moment (debyes) X Y Z Total from point charges -14.461 -6.319 -8.237 17.801 hybrid contribution 0.263 0.742 0.829 1.144 sum -14.197 -5.576 -7.407 16.956 Atomic orbital electron populations 1.22690 0.81640 1.02374 0.99706 1.87885 1.19196 1.28743 1.95369 1.22596 0.94712 0.83977 0.99694 1.21977 0.92327 0.97791 1.04659 1.20214 0.95238 0.88020 0.85658 1.46124 1.59942 1.24794 1.05297 1.20026 0.79971 0.85347 0.83484 1.90630 1.39643 1.26721 1.83816 1.22896 1.02038 0.96931 0.94932 0.87705 1.23505 1.01225 0.92830 0.84044 1.88876 1.91139 1.32687 1.16422 1.22776 0.99190 0.84757 0.92046 0.91202 1.21925 0.99842 1.02262 0.96616 1.22939 1.03934 0.98027 0.92444 1.22418 0.99214 1.00558 0.95834 1.20864 0.86569 0.91944 0.98685 1.44011 0.99045 1.64488 1.23709 1.19154 0.97956 1.32986 0.88497 0.91907 1.25158 0.99860 0.98312 0.95837 1.69976 1.24010 1.47765 1.12811 0.86286 0.81893 0.77791 0.80722 1.21417 1.21713 1.20448 1.20670 0.99397 0.86792 0.87643 1.22601 0.92535 1.02025 1.01851 0.89935 0.94257 0.94431 0.93243 0.93949 0.89237 0.90646 0.76724 0.88322 0.90773 0.92024 0.92006 0.91303 0.88540 0.90259 0.92542 0.90514 0.92584 0.96879 0.93613 0.89756 0.96528 0.92147 0.90986 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 0.03 0.32 11.01 101.05 1.11 1.43 16 2 O -0.39 -5.42 10.70 -35.23 -0.38 -5.79 16 3 C 0.07 0.87 5.50 37.16 0.20 1.08 16 4 C -0.13 -1.95 4.32 -26.73 -0.12 -2.06 16 5 C 0.19 3.07 0.35 -131.78 -0.05 3.02 16 6 N -0.71 -10.13 3.34 -47.57 -0.16 -10.29 16 7 C 0.53 7.79 6.32 -10.99 -0.07 7.72 16 8 O -0.53 -9.46 11.75 5.55 0.07 -9.40 16 9 C -0.15 -1.76 3.52 -89.77 -0.32 -2.08 16 10 H 0.10 1.05 8.14 -51.93 -0.42 0.63 16 11 C 0.06 0.79 7.15 38.21 0.27 1.07 16 12 O -0.37 -5.09 11.19 -35.23 -0.39 -5.48 16 13 C 0.07 0.81 4.05 -26.16 -0.11 0.70 16 14 H 0.07 0.82 8.14 -51.93 -0.42 0.39 16 15 C -0.15 -1.36 9.37 37.16 0.35 -1.01 16 16 C -0.14 -1.58 6.04 -25.21 -0.15 -1.74 16 17 C -0.14 -2.17 4.72 -26.61 -0.13 -2.30 16 18 C 0.15 2.75 6.24 -3.71 -0.02 2.72 16 19 N -0.59 -13.92 2.98 -172.32 -0.51 -14.43 16 20 C -0.26 -6.80 9.58 -15.06 -0.14 -6.94 16 21 H 0.06 1.64 7.85 -52.49 -0.41 1.23 16 22 C 0.01 0.20 5.04 -17.43 -0.09 0.11 16 23 N -0.90 -25.68 11.09 55.49 0.62 -25.07 16 24 Si 0.90 21.44 29.57 -169.99 -5.03 16.42 16 25 H -0.29 -6.85 7.11 56.52 0.40 -6.44 16 26 H -0.29 -7.00 7.11 56.52 0.40 -6.60 16 27 H -0.28 -6.47 7.11 56.52 0.40 -6.07 16 28 C 0.18 4.20 4.99 -3.71 -0.02 4.18 16 29 C -0.15 -2.93 4.71 -26.61 -0.13 -3.05 16 30 H 0.08 0.68 8.14 -51.93 -0.42 0.25 16 31 H 0.04 0.34 8.14 -51.93 -0.42 -0.08 16 32 H 0.04 0.33 8.14 -51.93 -0.42 -0.09 16 33 H 0.05 0.60 6.27 -51.93 -0.33 0.27 16 34 H 0.04 0.54 7.45 -51.93 -0.39 0.15 16 35 H 0.09 1.54 6.22 -51.93 -0.32 1.21 16 36 H 0.07 1.14 8.14 -51.93 -0.42 0.72 16 37 H 0.40 5.08 7.19 -40.82 -0.29 4.78 16 38 H 0.10 1.14 8.14 -51.93 -0.42 0.71 16 39 H 0.07 1.13 8.04 -51.93 -0.42 0.71 16 40 H 0.06 0.54 8.14 -51.93 -0.42 0.12 16 41 H 0.06 0.55 8.14 -51.93 -0.42 0.13 16 42 H 0.07 0.52 8.14 -51.93 -0.42 0.10 16 43 H 0.10 1.30 6.90 -51.93 -0.36 0.94 16 44 H 0.08 0.80 7.70 -51.93 -0.40 0.40 16 45 H 0.06 0.72 6.35 -51.93 -0.33 0.39 16 46 H 0.08 1.25 8.14 -51.93 -0.42 0.83 16 47 H 0.06 1.05 7.93 -51.93 -0.41 0.64 16 48 H 0.01 0.24 6.89 -51.93 -0.36 -0.12 16 49 H 0.25 7.06 8.31 -40.82 -0.34 6.73 16 50 H 0.08 2.28 6.14 -51.93 -0.32 1.96 16 51 H 0.02 0.41 7.74 -51.93 -0.40 0.00 16 52 H 0.06 1.20 8.14 -51.93 -0.42 0.78 16 53 H 0.07 1.47 6.26 -51.93 -0.33 1.14 16 LS Contribution 399.81 15.07 6.03 6.03 Total: -1.00 -30.91 399.81 -8.43 -39.34 By element: Atomic # 1 Polarization: 15.10 SS G_CDS: -9.27 Total: 5.83 kcal Atomic # 6 Polarization: 2.25 SS G_CDS: 0.61 Total: 2.86 kcal Atomic # 7 Polarization: -49.74 SS G_CDS: -0.06 Total: -49.79 kcal Atomic # 8 Polarization: -19.96 SS G_CDS: -0.71 Total: -20.67 kcal Atomic # 14 Polarization: 21.44 SS G_CDS: -5.03 Total: 16.42 kcal Total LS contribution 6.03 Total: 6.03 kcal Total: -30.91 -8.43 -39.34 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. ZINC001151198734.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 -72.078 kcal (2) G-P(sol) polarization free energy of solvation -30.909 kcal (3) G-ENP(sol) elect.-nuc.-pol. free energy of system -102.987 kcal (4) G-CDS(sol) cavity-dispersion-solvent structure free energy -8.426 kcal (5) G-P-CDS(sol) = G-P(sol) + G-CDS(sol) = (2) + (4) -39.336 kcal (6) G-S(sol) free energy of system = (1) + (5) -111.414 kcal 1SCF WAS SPECIFIED, SO GEOMETRY OPTIMIZATION WAS NOT USED Total computer time = 1.51 seconds