following reactions using these 3 methods PM3 HF B3LYP Use the Routine basis

Following reactions using these 3 methods pm3 hf

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following reactions using these 3 methods: PM3, HF, B3LYP. Use the “Routine” basis set. Compare your reaction energies with ex periment. What percentage error do you get for each method? Reaction Experimental Reaction Energy (kcal/mol) HCCH + 3H 2 2CH 4 -105 HCN + 3H 2 CH 4 + 2NH 3 -76 PN + 3H 2 NH 3 + PH 3 -45 PP + 3H 2 3PH 3 -44 PM3 (kcal/mol) HF (kcal/mol) B3LYP (kcal/mol) HCCH 71.38215 -48373.2919 -48695.37309 H2 -2.56851 -694.29654 -723.86496 CH4 17.77293 -25290.6696 -29275.53867 -28.13076 -125.15769 -7684.10937 % Error 73.2088 19.1978 7218.1994 HCN 46.94445 -58493.622 -58842.75159 H2 -2.56851 -694.29654 -723.86496 CH4 17.77293 -25290.6696 -29275.53867 NH3 26.69688 -35365.7821 -35598.67794 31.92777 -35445.7221 -39458.54808 % Error 142.0102237 46539.10807 51819.14221 PN 36.29934 -248922.491 -249508.0955 H2 -2.56851 -694.29654 -723.86496 NH3 26.69688 -35365.7821 -35598.67794 PH3 19.94265 -215712.037 -216147.3779 18.04572 -72.43866 -66.36546 % Error 140.1016 60.9748 47.4788 PP 35.9352 -429261.92 -430050.474 H2 -2.56851 -694.29654 -723.86496 PH3 19.94265 -215712.037 -216147.3779 31.59828 -215791.3019 -216220.0648 % Error 171.8142727 490334.777 491309.2381
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5. Calculate the isomerization energies for the following compounds using these 3 methods: PM3, HF, B3LYP. Use the “Routine” basis set. Compare your isomerization energies with experiment. What percentage error do you get for each method? Recall that the isomerization energy is the energy to convert one isomer to another isomer, and determines which isomer is more stable. Isomers Experimental Isomerization Energy (kcal/mol) CHN: hydrogen cyanide, hydrogen isocyanide 14.5 CH 3 NO: formamide, nitrosomethane 62.4 CH 3 H 6 O: acetone, oxetane 30.8 C 2 H 5 NO: glycine, nitroethane 69.7 Experimental PM3 (kcal/mol) HF (kcal/mol) B3LYP (kcal/mol) hydrogen cyanide 46.94445 -58493.62197 -58842.75159 hydrogen isocyanide 332.0667 -58236.66009 -58547.08188 14.5 285.12225 256.96188 295.66971 % Error 1866.360345 1672.150897 1939.101448 formamide 5.23782 -106366.307 -106981.8042 nitrosomethane 45.03807 -106318.2973 -106934.6231 62.4 39.80025 48.00978 47.181078 % Error 36.21754808 23.06125 24.38929808 acetone 7.01064 -120868.9715 -121628.8275 oxetane 31.88493 -120837.8594 -121595.6498 30.8 24.87429 31.112109 33.17769 % Error 19.23931818 1.013340909 7.719772727 glycine -10.35153 -179342.3337 -179103.5864 nitroethane 338.73651 -177800.0704 -178809.6404 69.7 349.08804 1542.26331 293.94603 % Error 400.8436729 2112.71637 321.7303156
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