Ab Initio Calculations of the Potential Surface for Rearrangement of 2,2,3,3-Tetrafluoromethylenecyclopropane to 1-(Difluoromethylene)-2,2-difluorocyclopropane

2006 ◽  
Vol 128 (51) ◽  
pp. 16676-16683 ◽  
Author(s):  
Haiyan Wei ◽  
David A. Hrovat ◽  
Weston Thatcher Borden
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Potential Surface

Ab initio studies of isocyanatoborane and difluoroisocyanatoborane; bent or linear BNCO chains?

1991 ◽  
Vol 69 (6) ◽  
pp. 1000-1005 ◽  
Author(s):  
Susan Ellis ◽  
Edward G. Livingstone ◽  
Nicholas P. C. Westwood
Keyword(s):  
Carbon Atom ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Potential Surface ◽  
Energy Difference ◽  
Basis Set ◽  
Basis Sets ◽  
Hartree Fock ◽  
Split Valence ◽  
Valence Basis Set

Ab initio calculating at the 3-21G, 6-31G*, 6-31G**, 6-311G*, and 6-311G** Hartree–Fock levels, have been performed on the unknown H2BNCO and F2BNCO molecules in order to establish the geometries of these isoelectronic propadienone analogues. For H2BNCO the double split valence basis sets lead to linear BNCO chains, whereas either a triple split valence basis set, or the inclusion of correlation to second order (MP2/6-31G*) gives trans-bent structures. These have angles at nitrogen of 153.6° (6-311G*) or 149.9° (MP2/6-31G*), with the potential surface for angle bending extremely flat, and 0.5 kJ mol−1 (6-311 G*) or 1.12 kJ mol−1 (MP2/6-31 G*) separating the C2v and Cs structures. For the bent structures there is a small trans-bend (4–6°) at the carbon atom. The F2BNCO molecule is also linear at the 3-21G level, but is, however, already trans-bent (145.6° at nitrogen, 175.9° at carbon) at the 6-31G* Hartree–Fock level; 1.47 kJ mol−1 separates the bent and linear structures. The triple split valence basis set 6-311G* leads to a further decrease in the angle at nitrogen (141.0°), and a similar NCO angle (175.9°), with the bent structure favoured by 3.85 kJ mol−1. MP2/6-31G* calculations give a minimum with an angle at nitrogen of 140.2°, and a bent-linear energy difference of 3.58 kJ mol−1. Key words: ab initio calculations, isocyanatoboranes, structures, quasilinearity, propadienone analogues.

Ab initio calculations of the potential surface for the 2A1, state of CH4+

1983 ◽  
Vol 105 (1-2) ◽  
pp. 31-36 ◽  
Author(s):  
J.M.García de la Vega ◽  
J.Fernández Rico ◽  
M. Paniagua ◽  
J.I. Fernandez-Alonso
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Potential Surface

Millimetre-wave and infrared spectroscopy of Br13 CN: anharmonic force field of cyanogen bromide from spectroscopic data and ab initio calculations

1997 ◽  
Vol 90 (3) ◽  
pp. 495-497
Author(s):  
CLAUDIO ESPOSTI ◽  
FILIPPO TAMASSIA ◽  
CRISTINA PUZZARINI ◽  
RICCARDO TARRONI ◽  
ZDENEK ZELINGER
Keyword(s):  
Infrared Spectroscopy ◽  
Force Field ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Spectroscopic Data ◽  
Cyanogen Bromide ◽  
Millimetre Wave ◽  
Anharmonic Force

Ab Initio Calculations of Defects in CdMnSe Semimagnetic Semiconductors

2020 ◽  
Vol 55 (1) ◽  
pp. 108-113
Author(s):  
M. A. Mehrabova ◽  
H. S. Orujov ◽  
N. H. Hasanov ◽  
A. I. Kazimova ◽  
A. A. Abdullayeva
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Semimagnetic Semiconductors
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