Acetone, ab initio calculations

Molecular mechanics (MM4) study of amines

“…Ab initio calculations were used to determine molecular mechanics parameters as long ago as 1972, 13 and subsequently they have been used more frequently as computer power increased enough to allow better results to be obtained more easily. [13][14][15][16] From our previous experience, if we can fit the experimental moments of inertia accurately for a group structures, we will also fit the MP2/6-311þþG(2d,2p) calculated structures [which we will hereafter refer to as MP2/B (for big basis)], allowing for the truncation errors 17 in the later [which we then refer to as MP2/ BC or BC (for big basis and corrected)], and for the interconversion of r z and r e structures. In this study, the MP2/BC calculations were used to provide some of the required information when the necessary experimental data were not available or were uncertain.…”

Refinement of molecular mechanics parameters for deformed benzene based on ab initio molecular orbital calculations

“…These preferences are well reproduced by our force field. anti-( 7) is 4.3 kcal mol-' more stable than syn- (7), and syn-( 8) is 3.8 kcal mol-' more stable than anti- (8). Whereas the experimental deformation angles of benzene rings are well reproduced by our force field and by MMP2(85) as summarized in Table 4, the deformation angles are overestimated by MMP2(82).…”

G3(MP2) Study of the C3H6O+• Isomers Fragmented from 1,4-Dioxane+•

“…The chemistry of C 3 H 6 O +• radical cations has been extensively studied both experimentally and theoretically. − These radical cations, in numerous isomeric forms, appear in the mass spectra of many organic compounds, such as 1,4-dioxane, 4-methyl-1,3-dioxolane, etc. More importantly, the C 3 H 6 O +• ionic systems participate in a wide range of rearrangement and dissociative processes. ,, In the C 3 H 6 O +• family, distonic ions deserve special attention because unique properties result from its separation of charge and radical sites.…”

“…The chemistry of C 3 H 6 O +• radical cations has been extensively studied both experimentally and theoretically. [1][2][3][4][5][6][7][8][9][10][11][12] These radical cations, in numerous isomeric forms, appear in the mass spectra of many organic compounds, such as 1,4-dioxane, 4-methyl-1,3-dioxolane, etc. More importantly, the C 3 H 6 O +• ionic systems participate in a wide range of rearrangement and dissociative processes.…”